We live in an age where the cosmetics industry is evolving at lightening speed. Almost no longer is a person using only face cream. Most of us use at least 3 products or more at a time. This is called cosmetic layering. The layering method has many advocates, but more and more opponents are also found.

Layering is a skin care technique that comes from Asia. This technique consists of applying various cosmetic products to the face in a certain order. We often think that this technique is popular only among Asians. Layering is a technique that is used by more and more people who dedicate more to their skin than just face cream.

How bad is layering cosmetic products really?

So, the opponents of layering accuse this method of applying amount of preservatives that exceeds the maximum concentration on the skin. Manufacturers rarely use the maximum amount of preservatives allowed. Maximum allowable concentrations are set so that even the most sensitive skin does not develop a reaction. Another thing to know here is that concentrations do NOT add up! Just as SPF does not add up, so do concentrations.

If you have 100 ml of tonic containing 0.1% phenoxyethanol and 250 ml serum containing 0.15% phenoxyethanol this is not 0.35% phenoxyethanol. Unfortunately, the calculation is not so easy. While you need to know that you cannot calculate the concentration of two different preservatives. The calculation is only possible for the same ingredient.

The calculation shows that the total concentration is 0.13%, which means that the concentration increase is minimal. Such deviations would only cause problems for people with really sensitive skin. So if you want, you still use face tonic as these preservatives will not “eat away” your face because of one coat anymore.

About the layering of several different preservatives, have you ever wondered that even in many cosmetics, many different preservatives are used to maximize product protection? If there is no scare on that product, then we don’t need to scold it here either.

How to layer Cosmetic Products Properly?

In the case of layering, there is one simple rule: always apply the least viscous product first. Then we continue with more viscous products. The skin care process is always started with water-based products, ie tonic, moisturizing serum, serum with active ingredients based on water. Water-based products make it easier to cross the skin and therefore need to be applied first.

Why would water-based products cross your skin?

We should think of the skin as a structure containing large molecules such as squalene, fatty acids, waxes, esters and triglycerides. These molecules are huge compared to water, but they are not clustered together like bricks, but there is some space between them. Because of this space between the larger molecules, water can flow from the skin (transepidermal water loss) and into the skin!

The most viscous products such as creams, oils or butter should be applied at the end. For the most part, these ingredients act emolliently and occlusively. Occlusive action means that these products form a water-tight film on the surface of the skin. So it is a good idea to apply a water-based serum before the cream or oil, as moisture will lock into the skin. Namely, the problems with applying oil first and then water-based serum are more problematic.

• The active ingredient in the serum would not reach the skin – water and oil were repelled, so the water-based serum would remain on the surface of the oil

• A drop of serum that would be on the surface of the oil would evaporate over time

So it’s a shame to throw serum away. However, we should be aware that no product forms an occlusive layer on the skin for a very long time. Also, occlusive creams that are designed to prevent moisture loss and other substances from penetrating the skin are not exactly flowering in the performance of their function.

Particular attention should be paid to the active ingredients

Some cosmetically active ingredients are very effective, but they are known to have poor skin penetration. An example of such an active ingredient is vitamin C (ascorbic acid), which crosses the skin barrier very poorly. Therefore, such ingredients should be used in the first stages of care so that they are as close as possible to the skin and thus have a greater chance of reaching the desired site.

What is the correct order of product layering?

We first start with a tonic to restore the skin’s natural pH. We continue with a water-based serum designed to moisturize the skin (hyaluronic acid, glycerol, ..) or a serum containing active ingredients (acids, vitamin C, vitamin B, peptides). The last step, as mentioned above, is to apply a cream or oil that locks all previously applied ingredients into the skin. During the day, make sure to apply sun cream!

Excessive use of the active ingredients can irritate the skin!

There is nothing wrong with layering cosmetics. As long as you layer products that mostly provide moisture, there are few things that could go wrong. However, the same does not apply to active ingredients. Using too many active ingredients increases the potential for them to “fight” with each other. This can cause skin irritation or incomplete passage into the skin. Incomplete passage causes the ingredient to remain on the skin, which can clog pores and subsequently cause pimples.

Because ingredients are more active and effective than ever before, they can also irritate the skin if you overdo them or use them in combinations that are not suitable for your skin type. One of the common mistakes with which we overload the skin is to combine products containing glycolic or salicylic acid with retinoids at the same time – so that we use both in the evening.

The stronger the product, the more conservative we are about the amount of application and the frequency of use.

What is your opinion on the layering of cosmetics?

We regularly protect our body with sunscreen, as today’s society is becoming more aware of the harmful effects of UV radiation. The only area on the body that we do not protect is hair. However, UV radiation can also affect the properties and appearance of hair. What happens to hair when the unprotected are exposed to the sun and what products can protect them?

Like other tissues, hair is made up mostly of proteins. Hair consists of 85% keratin, 1-3% lipids, trace metal ions (aluminum, chromium, calcium, magnesium), water and pigments. UV rays have a high protein breakdown ability, so it’s no surprise that summer can be a difficult period for the hair.

UV hair protection is important

Many people are unaware that their hair is also affected by UV radiation. In the scientific literature, hair damage from UV radiation is associated with dryness, increased breakage and split tips, lower shine, and increased roughness of the hair surface. Not all of these changes occur immediately or all in the same place.

UVB radiation affects the hair approximately 5 μm below the surface. For healthy hair, it is primarily the outer layer. In the case of hair that has already been severely damaged by intensive bleaching and heat treatments, the outer layer may be absent. In this case, UVB radiation is exposed to the cortex of the hair. UVA radiation is less intense, but it can penetrate deeper and may affect the entire cortex.

All The Ordinary and NIOD products can be purchased at Beautyology.eu.

To some extent, hair can protect itself

Melanin is a pigment that is responsible for skin and hair color and protection against the harmful effects of sunlight. An interesting fact is that blacks are rarely burned by the sun, as their melanin is significantly more active than ours and therefore protects them from burns. The same goes for hair. Eumelanin, which is present in individuals with darker shades of hair, is more photostable than pheomelanin, which is predominant in redheads and those with lighter hair. Therefore, darker hair is more protected than lighter hair.

Melanin works by disabling the free radicals that form when exposed to UV radiation. This prevents free radicals from affecting keratin, the main protein in the hair. In the process, damage to the melanin molecule occurs, which turns light. This is the reason we have lighter hair at sea than we usually do.

Why does hair get grey and why isn’t it protected?

Hair turns gray when pigmentation stops. Pigments are secreted by stem cells that begin to die off. The stem cells in the upper layer of the skin develop into melanin-producing cells. Melanin-producing cells are called melanocytes. Melanocytes transfer the pigment to growing hair, making the hair a distinctive color. As we age, the stem cells start to die off and no longer develop into melanocytes, so the hair becomes gray.

When the hair ages, there are no more melanin-forming cells. So when melanin is gone, we no longer have a molecule to protect our hair from the harmful effects of UV radiation. Exposure to the sun can do more damage to such hair, as they are less resilient. A group of people with such hair needs the highest UV protection.

In what ways can the sun affect the properties of your hair?

  • Formation of free radical substances (ROS)
  • Discoloration
  • Disruption of disulfide bridges
  • Changes to the cuticle
  • Some amino acids absorb UV light and form free radicals that break the disulfide bonds.
  • In darker hair, melanin can be photooxidized, while in lighter hair, some amino acids are destroyed, causing discoloration.
  • Keratins in the hair are interconnected by disulfide bonds – bridges. Light breaks them down to form cysteic acid, which in turn makes hair less resilient and less elastic.
  • Melanin is found in the inner layer of the hair, but not in the outer layer, so it is not protected. After that, it is most exposed to UV radiation. The “roofers” that make up the cuticle are more open and lose weight.

Are UV protection products the hair solution?

For the protection of hair we use various products to which manufacturers add UVA and UVB filters as classic sunscreens that we use to protect the skin. The main problem with these products is that they cannot be applied evenly over the entire surface of the hair, which means that some parts of the hair are not protected. Another challenge is to create a sun protection formulation that will adhere to the hair shaft. In addition, it is almost impossible to apply a uniform thickness of sunscreen to all your hair without looking greasy.

How do UV hair protection products work?

Some shampoos for colored hair contain UV filters, as this should prolong the color lifespan (prevent fading). However, the problem again arises with shampoos as these products need to be completely rinsed off the surface of the hair and thus some UV filters can also be flushed. As a result, the ability to protect hair is limited.

A better approach to UV hair protection is to use balms that form a film on the surface of the hair that is not rinsed between 15-30 minutes. As a result, UV filters can adhere better to hair and offer more effective protection.

Hair styling products are probably the most effective in providing photoprotection. These products include non-rinse balms, gels and hair sprays.

If you massage balms that do not need to be rinsed, they will act as a heat protection agent and UV protection just before drying, as they remain on the hair.

The most effective products that protect against UV radiation are hair dyes

Non-pigmented hair (white, gray) is more prone to UV damage than pigmented hair. This means that molecules of hair dye trapped inside the hair provide some protection against UV damage. Although hair dyes damage the hair tissue, this way the hair is protected from the harmful effects of UV radiation. Hair coloring causes damage to the hair fibers, but when the hair is exposed to prolonged periods of UV radiation, the antioxidant effect of the dye that binds inside the hair outweighs the initial detrimental effect of dyeing. Hair dyes act as antioxidants that prevent the disulfide bonds in keratin from breaking.

What do UV hair protection products contain?

First of all, it should be emphasized that the regulations in the field of hair protection are not as strict as in the field of skin protection. We cannot determine the exact SPF protection factor for hair products. However, there is a Hair Protection Factor (HPF) based on the change in mechanical properties between protected and unprotected hair. There is also a Radical Hair Protection Factor (RHF) that differentiates products based on their ability to prevent ROS from UV radiation.

The products contain UV filters, silicones that form a hair film and antioxidants. In addition, hair protection products also contain moisturizers, emollients, antistatic agents as well as thermal hair protection substances. Natural extracts that protect the hair include walnut, beech, aloe vera, green tea, chamomile, lotus and oils such as monoi.

All The Ordinary products have been donated to create this post by Beautyology.eu.

Since the use of sunscreens has been on the rise, they have gained many advocates as well as many opponents. Opponents of sunscreens claim that they block the synthesis of vitamin D, which is essential for our health. There are also extreme opponents who claim that using sunscreens is more harmful than unprotected sun exposure. However, is it true that sunscreens block vitamin D synthesis?

Basic information on vitamin D

Vitamin D acts as a hormone in the body and is synthetized by UV light. Vitamin D comes in two forms (D₂, D₃). Vitamin D₂ is obtained from plant nutrition and oral supplements. Vitamin D₃ is mainly obtained by exposing the skin to ultraviolet B (UVB) radiation in sunlight and consuming foods such as oily fish. Vitamin D₂ and D₃ are metabolised in the liver and kidney to 1,25-dihydroxyvitamin D or calcitriol, which is a biologically active form. Calcitriol plays an important role in regulating the metabolism of calcium, phosphate for maintaining metabolic functions and for skeletal health.

How can one get vitamin D?

Vitamin D is also found in mushrooms, wheat germ oil, egg yolk, liver and fish oil. Vitamin D content in most foods ranges from 50 to 200 units per serving. Therefore, food cannot provide enough vitamin D, which is why most people synthetize it after sun exposure. Sun-induced vitamin D synthesis is strongly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, use of sunscreens, passage through glass and plastic, and age.

Interesting fact: Even when older people are regularly exposed to sunlight, they produce 75% less vitamin D3 than young people.

Inadequate vitamin D intake can lead to postmenopausal osteoporosis and reduced bone density. Low vitamin D intake is also associated with heart and vascular diseases, depression, dementia and other conditions.

How is vitamin D synthesized after sun exposure?

Vitamin D3 can be produced in the skin when exposed to ultraviolet radiation B (UVB), so it is possible to increase vitamin D3 levels by exposure to UVB rays. During exposure to sunlight, radiation with a wavelength of 290–315 nm penetrates the skin. Most of this UVB radiation is absorbed in the epidermis, so when exposed to sunlight, most of the vitamin D3 is produced in the skin, in the living cells of the epidermis.

A quick recap on UV radiation

As we already know, exposure to UV radiation is not safe. Namely, we divide the UV spectrum into ozone-retained UVC rays, UVB rays that cause sunburns, UVA rays that cause photoaging. Unnecessarily prolonged exposure to UV light without protection can lead to skin cancer. For a reason, sunscreens have been developed to protect us from the harmful effects of UV radiation. Sun creams are designed to absorb and partially repel UVB radiation.

All The Ordinary and NIOD products can be purchased at Beautyology.eu, where you can use code COSMEDOC10.

If sunscreen blocks UVB rays does it block vitamin D synthesis as well?

Well, here we are. Where scientists from different disciplines are arguing with each other. Last time, I heard from a colleague that one dermatologist claimed that reduced vitamin D synthesis from sunscreens is more harmful than unprotected sun exposure. To put it mildly, I was almost hit by a stroke, but let’s go down the line. Sunscreen with sun protection factor (SPF) 30 absorbs approximately 96% of UVB radiation. So, by adding 2 + 2, topical application of sunscreen with SPF 30 reduces the skin’s ability to produce vitamin D3 by the same amount, ie 96%.

In principle, we calculated that only 4% of UVB radiation can access our skin with SPF 30, which is a very low chance for vitamin D synthesis, right? But this is where  you need to ask yourself how much sunscreen you really apply to your skin. In order to achieve the protection stated on the packaging – so in our case SPF 30 we need to apply 2mg / cm2 of skin. For the whole face, this means two full fingers of the cream.

A short calculation to back up my claims

The average surface area of ​​all skin in an adult is 1.5-2.0 m². So if we need to apply 2mg / cm² the calculation is as follows.

The result is 32 g per coat. Therefore, 1/3 of the entire 100 ml tube of sunscreen should be used to properly protect the entire body. Of course, we did not take into account that the sunscreen should be reapplied every 2 hours.

Let’s be real, we apply such a small amount of sunscreen to the body that the question is if we have an SPF protection factor of 5. So with SPF 5, we are about 70% protected against UVB radiation. This may sound like a lot, but this time it can pass as much as 30% of UVB radiation to the skin! Not to mention some body parts that are not usually protected at all. Or maybe we are in the shade and don’t put sunscreen on because the UVB rays can’t reach us. All of these unprotected parts allow 100% passage of UVB radiation and thus synthesis of Vitamin D, but also increased chances of skin cancer.

UVA protection is beneficial for Vitamin D

A number of studies investigating the influence of sunscreen on vitamin D synthesis have found that the use of sunscreen is likely to have minimal impact on vitamin D. UVA rays have no effect on vitamin D synthesis, although one in vitro study showed that UVA2 (315–340 nm) can cause vitamin D to break down, in which case protection against UVA may be beneficial for vitamin D production.

Controlled field studies with true sun exposure are the best way to determine the effect of sunscreen on vitamin D synthesis. The results of such studies report that no change in serum 25 (OH) D3 vitamin concentration occurs despite the use of sunscreen.

In fact, most studies published to date have shown no association between the use of sunscreens and vitamin D deficiency, nor with regular use of SPF> 15. In general, other protective methods (eg, shading, wearing protective clothing and long sleeves) ) affect vitamin D status more than using sunscreens.

UV radiation is more dangerous than sunscreens

Daily skin protection is recommended for all skin phototypes. This includes staying in the shade, wearing headgear and clothing, wearing sunglasses, and applying broad-spectrum sunscreen. These strategies will help prevent sunburn and skin cancer. The use of sunscreen for daily sun protection does not compromise the synthesis of skin vitamin D synthesis, even when the sunscreen is used in the predicted amounts (2mg / cm2). Increasing UVA-PF in sunscreens, however, even improves vitamin D3 production.

In case of reduced vitamin D level, this should be replaced. Oral supplementation is easy and does not pose significant risks. The risk-benefit calculation shows that, instead of sunbathing, it is better to take nutritional supplements with this vitamin to increase vitamin D3 levels.

Skinfairytale sent two new products to the market before the summer and these are the natural body makeup Chocotan and the natural Aftersun lotion. Why is natural Chocotan a better choice than classic self-tanning product and what kind of wonders does the Aftersun lotion do?

The only light spectrum we talk about is UV light spectrum. However, the light spectrum also contains visible light and IR radiation. What are the effects of visible light on the skin and should we be protected from visible light as well?

Firstly, let’s get it clear. What is visible light?

Visible or blue light is an electromagnetic wavelength between 400 and 700 nm. This spectrum is able to be seen by a naked eye, well to most of the population. Some people aren’t able to see the full spectrum and somebody can see beyond the spectrum.

When a beam of visible light reaches to a body, the photons can be reflected or absorbed on the surface of this body. They can penetrate the body or be absorbed or dispersed into components. The last option for photons is to continue their path undisturbed.

Why is the sky more blue on days with no clouds and at sunset yellow or red?

The sky is blue because the blue photons are better scattered by the air molecules and are directed to our eyes. At sunset, we can see the sky red, because blue photons are scattered away so we can’t see them and on the , there are only red or yellow photons, which can be detected by a naked eye. At sunset, the journey of the light through the atmosphere to our eyes is longer than it is at midday.

Why do we see blood red?

Blood is red because it absorbs blue and green wavelength and red is being reflected. The grass is green because it absorbs red and blue wavelengths and the green is being reflected.

Energy dynamics

Why are we explaining all this? Molecules are able to form new chemical structures with other molecules being particular states. They can also transfer an electron to other molecules to create reactive oxygen species (ROS), which are able to destroy our DNA. Studies have shown that visible light doesn’t only affect the ROS but also matrix metalloproteases.

Visible light and skin

Melanin is responsible for skin color and can be found in the epidermis. Melanin partially absorbs visible light, which can cause hyperpigmentation and uneven skin tone. The dermis contains blood vessels that are capable of absorbing blue and green light. Other photons, which are scattered around can penetrate into adipocytes in subcutis. Fat cells are capable of partial absorption of red photons.

A candlelight dinner is therefore good for people with mature skin. The blood vessels in mature skin are closer to the surface and can absorb more blue and green light and the wrinkles are more visible on daylight. When we are next to candles this doesn’t happen, because candles absorb only red and yellow photons, which aren’t absorbed by blood and vessels are less visible (consequently are also wrinkles less visible).

Per unit of energy, visible light is 20 to 30 times less effect than UV, but there is 10 to 15 times more visible light in the solar spectrum than UV, so visible light cannot be neglected.

Good and bad qualities of visible light

Visible light helps to promote photoageing. It’s able to promote inflammation and consequently, inflammation phenomenon accelerates ageing. All that affects our DNA.

Those were bad news, but there are also good ones.

The use of foundation (powders) and other decorative cosmetics prevents visible light from harming us. Decorative cosmetics in fact protect us from the negative effects of visible light. Moreover, visible light even shows therapeutic effects (treatment of psoriasis, eczema, acne).

Acne

Porphyrins in Cutibacterium acnes (before Propionibacterium acnes) are particularly sensitive to visible light. When the skin is exposed to visible light, endogenous toxins are formed. They kill the microorganisms which are responsible for acne formation. Visible light alleviates inflammation, redness and aesthetic discomfort.

Bilirubin

Another positive effect is seen in premature babies. Their system isn’t capable of removing bilirubin. The accumulation of bilirubin increases the risk of jaundice which can harm brains and liver. Premature babies are irradiated with visible light because it’s able to reduce bilirubin to normal levels.

So how safe is the visible light?

If the blue light is used only for a short time, it doesn’t show negative effects and should be safe (skin testing in vivo). However, we don’t know what it would be like to be exposed to the visible light for a long time.

What seems curious is that while studying visible light, the radiation in the spectrum between 410 and 420 nm showed cytotoxicity to human fibroblasts. But wavelengths between 453 and 480 nm didn’t. This is pretty logical since the first two wavelengths are closer to UV radiation and exhibit similar effects as UV light, while the other two are longer wavelengths and they don’t show these effects. Therefore, it is believed that sunscreens should have UV protection above 400 nm as well.

Where can a blue light be found?

The most common source of blue light is electronic devices such as screens, tablets, smartphones, and LEDs. Studies suggest that blue light is also expected to have negative effects on our eyes.

What substances can protect us from the negative effects?

So far, has shown activity in the visible spectrum only: titanium dioxide, zinc oxide, bis-benzotriazolyl tetramethylbutylphenol (MBBT), but their protection is low. They tested 3 % titanium dioxide and 4 % MBBT, which were expected to block 50 % of blue light between 400 and 500 nm.

The microalgae extract Scenedesmus rubescens reduces the negative effects of blue light, also vitamins B3 and B6 have been tested on preventing blue light negative effects (table in “Into the blue”). Vitamin E also provides good protection against visible light.

Tested ingredients (vitamin B3, B6 and algae extract) inhibit the formation of ROS caused by blue light (source: Mendrok-Edinger C., Campiche R., Gadsinski K., Schuetz R. Into The Blue. Cosmetics and Toiletries 2018)

Also, carotenoids, which act as antioxidants, are able to protect the skin from the negative effects of blue light. In addition, their maximum activity is precisely in the visible light spectrum, so they may represent potential biological protection against blue light.

Every facial care should begin with proper skin cleansing. Lately there is a lot of talk about “double cleaning” of the skin. Do you know what the purpose of the double cleaning is, and why most use this method? How does micellar water work and how do soaps work?

What is the purpose of cleaning the skin?

Throughout the day, we are exposed to our cosmetic products and various environmental pollutants. With our hands we touch our faces, and in the winter there is a lot of smog and all this accumulates on the surface of our skin and in the pores. Because of all the impurities that accumulate, the skin needs to be cleaned in order to keep it healthy. Under all pollutants, pores become clogged and this may be reflected as an increased excretion of sebum or the formation of comedons.

Skin should also be cleaned in the morning. In the morning, it is necessary to wash the cosmetic products that were applied in the evening, from the face. At the same time, dust is on our head, which is also passed on to our face. So, before the next morning you start to apply morning care, first cleanse your skin.

How do cleaners work?

Surfactants

We know that water and oil do not like eachother. The oil is lighter than water and will therefore always float above the water, and these two substances will not be united by themselves. The reason for this is the excessive surface tension between them. For stabilization, however, a substance is needed, which will reduce the inter-phase voltage, and these are surfactants.

One of the most typical activities for surfactants is cleaning. Surfactants are key ingredients of cosmetic products such as soaps, cleansing gels, shampoos and sparkling baths.

Surface-active substances are substances that, due to their chemical structure, are distributed at the boundary between the two phases. The characteristic of surfactants is the presence of a hydrophilic and hydrophobic part in the chemical structure. Surfactants influence the dissolution of substances with different mechanisms.

Solubilization

Solubilization means increasing the solubility of a poorly water-soluble substance with surfactants. The mechanism involves “catching” (adsorbed or dissolved) molecules in the micelles.

Cleaners work on the principle of solubilization. By solubilizing the substance, the solubility and dissolution rate of the substance is increased. More broadly, solubilization also involves the use of other methods of increasing solubility, such as, for example, use of co-solvent.

How does micellar water work?

The main ingredients of micellar water are water and one or more surfactants.
We can imagine micelles as a leaf that is folded back into itself. The way it folds depends on the media that surrounds it. In the aqueous medium, the micelle has hydrophobic tails on the inner side and the polar head on the outside. If the medium is an organic solvent, then the components of the micelle are turned – the polar heads are inward, and the hydrophobic chain is outwards.

By increasing the amount of surfactant in the aqueous solution, the surface tension drops until the molecules fill the boundary surface between the aqueous and the oil phase. At a given concentration, the surfaces between water and oil are saturated and surfactants begin to aggregate and form aggregates called micelles. The concentration at which micelles begin to form is called critical micelle concentration.

When the micellar water is applied to the face, the micelles capture the oily components into their interior. This happens because they are arranged in such a way that the lipophilic (hydrophobic) tails look at the place where the oil and other impurities are caught.

Why is it necessary to rinse off micellar water?

You must have heard that the micellar water needs to be washed off. Because they contain surfactants they can have a negative effect on the skin. Surface-active substances differ, some are gentle (eg syndrome), some are more aggressive (sodium lauryl sulphate).

It is known that the constant use of surfactants for cleaning has a negative effect on the skin. For decades, scientists have thought that the mechanism for damaged skin barrier is the removal of lipids from the porous layer. Recent studies show that surface-active substances cause denaturalization of skin proteins and interact with keratin.

Types of cleaning agents

Soaps

Soaps are a general term used for preparations containing alkaline (basic) salts from mostly solid fatty acids. Classical soaps are the most alkaline formulations with a pH value of between 9 and 10.

Glycerine soaps are made from glycerol and natural glycerine oils. Glycerin is a humidifier, which is often used for moisturizing and protecting the skin. This helps neutralize the effect of drying alkalis.

Superfatted soaps: contain glycerol, but also a wide range of lipids that help restore the lipid layer in the skin (triglycerides, natural oils and fats).

Antibacterial soaps include antibacterial substances such as carbanil and triclosan.

Soap with the syndets

They are made of surfactants, such as sulfuric acid esters and isoethates of fatty acids. These soaps have a pH of 5 to 6. However, they contain synthetic components.

Liquid cleaning agents

They can contain several natural and synthetic surfactants and various moisturizers and lipids.

Oil-free cleaning agents

Rich in fatty alcohols that allow you to clean your skin without the need for water. These formulations are rapidly dried and include moisturizing agents to prevent possible irritation.

Cleaning creams

These formulations are a mixture of surfactants, lipids and waxes. These have traditionally been used to treat patients with atopic dermatitis due to the high fat content that can form a protective barrier on the skin.

Double skin cleansing

Double cleaning is a method where two different types of cleaning agents are used, one after the other. In the case of two cleaning, first clean your face with clean oil, oil-based cleaning fluid or cleansing milk. Then there is followed by purification with a water soluble cream, gel or foam. Cleaning with oil-based products helps dissolve make-ups and water-resistant juicy creams. Compared to pure oils, modern cleaning oils contain emulsifiers that allow the oil to mix with water and form a milk emulsion. This facilitates skin rinsing.

How to properly clean the sun cream from the face?

A non-waterproof sun cream can be washed with a cleansing gel or oil, and waterproof sunscreen cleans only cleaning oil. The sun protection product can be partly removed with water, but this is a less effective way, compared to cleansing gel and oil. In addition, cleaning oil, in comparison with the cleansing gel, can less irritate the skin and dry it less.

Hair is exposed to chemical and mechanical stress and stress from the environment daily. All this leaves the consequences of hair, such as weaker, brittle hair and lost hair shine. For the purpose of restoring the hair surface, we use cosmetic hair restoration products, especially hair balms. This time, in Slovenian cosmetics, we represent the brand Eterika, which created the entire line of hair restoration products.

First, some hair facts

Human hair is naturally the same as all epidermal appendix that are typical of mammals. Their main function is to protect the body from external factors. The scalp differs from the skin on other parts of the body, as it is full of large hair follicles from which long hair fibers grow. A large sebaceous gland is attached to each of the hair fibers. Each hair is composed of the shaft, the cortex and the core. The shaft of the hair is an envelope that protects against the ingress of water and consists of several layers of cells that overlap like tiles.

Straight and curly hair are composed of different cells

Two types of cells are present in the cortex: orthocortic and paracortic. Paracortic cells having a higher density are more resistant to moisture and are characterized by flat hair, and lower-density orthocortic cells are more sensitive to moisture and are characteristic of curly hair.

Chemical composition of hair

Like other tissues, hair is also made mostly from proteins. The hair consists of 85% keratin, which has a very high content of sulfur-containing amino acids (15% cystine). Hair fibers consist of 1-3% lipids, trace metal ions (aluminum, chromium, calcium, magnesium), water and pigments.

Fun facts about hair

Hair has two basic properties—strength and elasticity. It is remarkably resistant; a single hair fiber can carry a weight of 100 g without breaking, and can extend by 20–30% when dry and 100% when wet without breaking. This resistance is due to the presence, composition and organization of the cortex protein keratin.

Hair damage and how to deal with repairing the hair structure

The number of consumers with damaged hair continues to grow due to external factors. There appear:

mechanical damage: combing, hair straighteners

chemical damage: hair dyeing and bleaching

environmental damage: sun, pollution

Hair after this kind of damage needs to be corrected at several levels from the middle of the cortex to the shaft. Hair conditioners are usually composed of filmmakers, such as silicones. The filmmakers cover their hair with a fine waterproof layer and thus slow down or prevent the penetration of active substances into the hair’s interior.

The role of hair conditioners

Hair conditioners restore the structure and affect the appearance of hair. Also, the use of hair conditioners can make it easier to comb and reduce the tension between hairs. Balms also increase the shine and volume of the hair and improve their structure. Among the hair restoration ingredients are mostly cationic surfactants such as stearalkonium chloride, cetrimonium chloride, dicytilimony chloride, PEG-2 cocochromic chloride and others.

The texture of the hair can also be restored in a completely natural way. In the case of Eterika, Anja created as many as 3 natural hair balms. The most important ingredients of Eterika’s Balm are emollients. These are lipophilic substances that give hair a shine. Emollients are distributed over the hair to form a transparent film that repels water.

Main ingredients in Eterika conditioners

Coconut oil

Aside from making a great moisturizer for hair and scalp, the oil has been used as a natural remedy to combat frizz, get rid of dandruff, remove and prevent lice and promote hair growth. Its antibacterial properties may ward off folliculitis, an infection of the hair follicles, and may also fight fungal infections, such as ringworm of the scalp.

Funfact: Did it ever happen to you, that you got a chewing gum in your hair? Coconut oil can even be used to extract chewing gum from hair.

While pure coconut oil can improve scalp health, therefore improving the conditions for growing thicker, fuller hair, it does not treat the underlying cause of hair loss and cannot be relied on for treating baldness related to dihydrotestosterone.

Argan oil

Argan oil is a versatile oil that helps hydrate and soften the hair. Argan oil is rich in oleic and linoleic acid, but also contains high levels of squalene and vitamin E, which act as antioxidants. Argan oil should naturally increase the elasticity of the hair and consistently renew the shine of the hair. Vitamin E is a lipophilic antioxidant that protects against free radicals. Lately, vitamin E is said to be an ‘anti-pollution’ component, as it should prevent harmful effects of the environment.

Behentrimonium methosulfate

This ingredient in derived from rapeseed oil. It is a very mild yet effective ingredient known for it’s de-tangling and hair thickening properties. Because this ingredient directly deposits onto the hair follicle to smooth out the cuticles, it’s highly regarded for its conditioning abilities. It can be found in many hair products like conditioner, detangler, shampoo and styling gel. It also acts as an emulsifying agent, gentle enough to be used in baby products that are left on the skin. When used in lotions and creams, it gives a soft and powdery after-touch to the skin.

Kako uporabljati balzame za lase?

Po umivanju lase utremo z brisačo, da zmanjšamo navlaženost las. Balzam razporedimo po dolžini las in počakamo nekaj minut za boljši učinek (3-5 min). Nato balzam izperemo. Pri suhih laseh lahko nanesemo balzam po celotni dolžini las, pri mastnih pa le po konicah, saj bo drugače balzam preveč zmastil že tako mastno lasišče. Pri zelo suhih laseh je skoraj nujna uporaba mask za lase.

Nasvet za najboljši možen učinek balzama: Balzam nanesemo na za dlje časa, lahko tudi čez noč, tako da lase zavijemo v vlažno brisačo ali plastično folijo. V balzam pa lahko kapneš tudi nekaj kapljic keratina.

Najina izkušnja z Eterika balzami

Na voljo so trije balzami in sicer za vse tipe las z vonjem vanilije, proti razcepljenim in suhim konicam s pelargonijo in sivko ter za neukrotljive lase s kokosom. Glede na to, da gre za balzam ima zelo bogato teksturo, v bistvu je že skoraj kot maska. Po uporabi se lasje zelo enostavno razčešejo in so mehki, ter sijoči. Da o vonju ne govorimo, saj zelo lepo dišijo, vonj pa se na laseh obdrži še kar nekaj časa.

Celotno ponudbo izdelkov Eterika si lahko ogledaš tukaj.

For sure you have been asking yourself if you have to nourish your skin in any other way than usual. While being at the beach skin needs more care because we are exposed to the sun that can burn us and sea salt drains the skin. So how to nourish the skin at sea? How to act in case of sunburns? How to nourish the skin to maintain the tan we have?

How to act in the case of sunburns?

Today, we are already aware of the harmful effects of sunbathing, but the sunburn can happen. Either this is because of the insufficient amount of sunscreen or excessive sunbathing. Burn is an acute skin inflammatory reaction that usually occurs 1-24 hours after sunbathing. The burn depends on the intensity and the wavelength of light. Erythema may occur, which may be accompanied by pain, swelling or even blisters. Of course, the best way is to prevent all this with the appropriate UVA and UVB protective sunscreens.

Not only does exposure to the sun lead to faster aging (photoaging), it can also cause the formation of lentigues, teleangiectasia (spider veins), skin cancer, etc., if we are exposed to the sun without protection.

We can cure sunburns with anti-inflammatory extracts!

In a case of sunburns, we shower with lukewarm or cold water and gentle cleansing agents. After showering, we apply lotions or creams like aftersuns. In case we are burned, cosmetic products should contain the following extracts that soothe the skin.

ExtractsHow they work
Chamomile (bisabolol, hamazulen)anti-inflammatory, wound healing, soothe the skin
Italian strawfloweradstringent, antimicrobial, anti-inflammatory, antioxidant
Oatantimicrobial, antioxidant, soothes the skin, against itching
Pot marigold
anti-inflammatory, wound healing, antiseptic

Shea Butter

Due to the content of terpenoids, it acts anti-inflammatory and antimicrobial. It also acts as an antioxidant and protects us from reactive oxygen radicals. It helps to restore the skin barrier and acts regeneratively.

Aloe vera against erythema

The study tested 97.5% aloe vera gel and 1% hydrocortisone in the cream, and 0.25% predicarbate in the cream, both of which are corticosteroids. The effect of natural extracts is delayed. Corticosteroids reduced the erythema after 24 hours, while the gel of aloe vera reduced the erythema only after 48 hours. Although it seems that the percentage of aloe vera gel is high, it did not show any hypersensitive reactions to the testee. So, the aloe vera gel reduces inflammation, but it is not necessary that the gel could be used for chronic inflammatory diseases. It can be used as an additional care, especially in after-sun products, instead of gels / creams containing hydrocortisone.

Usually, oils rich in omega-3 and / or omega-6 are commonly used to treat sunburns, as they work regenerative and anti-inflammatory. We can also use the right antioxidants that prevent the harmful effect of ROS on our DNA. Some studies have shown that vitamin D also helps to relieve the burns produced in the sun.

Tan preservation

Well, the other option is to succeed in getting a healthy tan, because the sun does not always burn us to red. We want to keep the tan as long as possible. One option for maintaining a tan are self-tanning products, where the difference in colour is noticeable, but is washed within 1 week.

How to prolong the permanence of tanned skin?

Carrot oil, which was present in the formulations at concentrations of 2, 4 and 6%, has been shown to have SPF factor. The measured SPF values ​​ranged between 4 and 7. This, of course, is not sufficient for proper SPF protection. Carrot oil also works antioxidant and rejuvenating, and at the same time it nourishes the skin properly. It is used as an oil that helps to extend the intensity of the tan. It usually leaves traces on clothes, as the right carrot oil has an orange colour, which does not disappear in the formulation, even if it is present only in 3%.

Cocoa butter

It has an SPF of about 3, which is not enough to protect us from sun rays, but it still works photoprotectively. At the same time, it works antioxidant and regenerative, as it contains phytosterols and vitamin E. It helps us preserve the tan that we already have.

How to take care of the hair?

We are sure that you have already noticed how our hair colour, whether natural or dyed, fades away while we are at the seaside. People with darker hair struggle with melanin photoxidation, and others with lighter hair with degradation of amino acids in keratin, which is the main structural protein in the hair. Darker hair is somehow better protected against fading than lighter shades.

UVA rays are mainly responsible for the loss of colour in dyed hair, as they penetrate all the way to the cortex where melanin and colour pigments are located. UVB rays are blamed for the fading of the natural hair colour as they percolate into all layers of hair.

Keratin is via cysteine converted into cysteic acid in the final phase. This, however, reduces the resistance of the hair and its elasticity. Therefore, the hair is drier, less shiny, and more difficult to brush through.

Hair cuticle which is the exterior layer is most exposed. Melanin is located in the cortex and is not capable of protecting  the cuticle against UV radiation. Radiation destroys proteins and lipids in the cuticle. Hair cuticle opens and the hair loses their softness. In UV radiation, ROS also develops and further destroys the hair.

Are cosmetics with UV filters the solution for hair care?

Until now, there was no excessive enquiry for such products on our market. But there are shampoos and balms with UV filters. In fact, an entire hair care line with UV filters. In hair cosmetics the same UV filters can be used as in sunscreens, but there are also quaternary and polysilicones that exhibits UV protection for hair, but not for the skin. Of course, there are natural oils and extracts that also help protect your hair from UV radiation.

UVA is mostly promoting the formation of ROS, while UVB destroys pigment named melanin (destroying it or bleaching it), and for changing mechanical abilities, as it breaks bonds in our hair (cysteine ​​present in keratin), which makes our hair fragile.

How to groom the face?

At sea, you do not usually need ” heavy care”. For most skin types, the use of rich and nourishing creams and oils in summer is simply too much. Overly enriched care can lead to the formation of clogged pores and pimples. Therefore, it is better to reach for moisturizing formulas. In addition to daily sun cream, it is also recommended to use serums with antioxidants, which will additionally support the function of the sun cream.

Tajka Selan

Mosquitoes are one of theworst ”pains in the neck” in the summer. The most disturbing noise is surely their “bzzzz” at night. In this blog, we’ll explain why the mosquito bites, why the bites itch and what we should use to get rid of the annoying and itchy mosquito bites.

Firstly something about mosquitoes!

There are nearly 3,500 different types of mosquitoes. When we say that we have been bitten by a mosquito, in most cases it’s by a female. Females are usually the ones that suck the blood of mammals. Women are drama queens, again :). Males are mostly fed with nectar only. The mosquitoes feed themselves from early dusk until the sunset.

Mosquitoes can be carriers of various diseases, most known to everyone is certainly malaria. The mosquitoes also carry dengue fever and yellow fever. Mosquitoes manage to transmit a disease to more than 700 million inhabitants per year. Only malaria kills 3 million people a year. It is true that tropical and subtropical areas are more exposed and the possibility of disease is greater, but this does not mean that Europeans are immune.

Tiger mosquitoes

They are a new species in Europe that originally came from Southeast Asia. It was first detected in Europe in 2006. It is mostly found near water and is really problematic.

Why are mosquito bites itchy?

We don’t notice the mosquito bite immediately, but only after a few minutes/hours. So, it’s not the mosquito bite that itches, but the immune reaction that follows the bite. Before the mosquito gets to the blood, it releases its saliva into the body. Substances in saliva prevent blood clotting during the sucking (anticoagulants), making their work much easier. Saliva also contains substances that are very immunogenic. Our body responds to these substances by making antibodies.

There are various types of immune responses. The reaction is carried out in a way that nothing happens at the first contact with the matter (first mosquito bite). At the first bite, the body is sensitized and memory cells are formed. But when have we ever gotten away with a single bite? When a mosquito bites us the next time, our body has already prepared memorial cells that then migrate to the point of the sting. At each subsequent sting, the immune response is faster.

Myth: ”Mosquitoes bite me because I have sweet blood”

The mosquitoes are said to more often sting younger people with hot skin and a strong body smell (not necessarily odor). They’ll love you even more due to the increased CO2 concentrations or in case you are wearing dark clothes or glitters.

How do get rid of mosquitoes with synthetic repellents?

DEET

N, N-diethyl-m-toluamide is a commercial ingredient used in repellents and it’s very effective. It is used for repellent activity against mosquitoes, ticks, fleas and other insects. According to studies, it irritates the skin.

How does it work?

There are 3 hypothesis, but in every case, it masks the scent and, consequently, the insects do not detect a person. DEET can only mask the smell that mosquitoes does not recognize or it changes to confuse the mosquito, and consequently, the mosquito does not recognize us as a host and will not sting.

Some repellents up for sale also contain up to 45 % DEET, which is an enormous amount and that can irritate the skin a lot.

A well-known synthetic repellent is also icardin, which also works against many types of insects. They are said to be less aggressive. Icardin is used in repellents up to 20 %.

Natural ingredients with repellent activity

Since the synthetic ingredients in repellents are unfriendly both for the ecosystem and for us, they have been looking for alternatives for repellent action in nature.

Essential oils of the camphor tree

The essential oil of camphor tree has proven to have a repellent effect. It also acts insecticidal, antifungal, antibacterial and as an antioxidant. Terpenoids and phenylpropanoids, found in leaves and bark, additionally contribute to the bioactivity of the camphor tree.

Curcumin

Is considered to be a cheap, non-toxic and easily accessible substance. You probably are much more familiar with the use of it in the kitchen. It is also a yellow dye that acts repellently and is used in cosmetics. It has positive effects on certain diseases, abnormalities, and syndromes.

Lemon eucalyptus

It produces citriodiol, which is an active ingredient in repellents. It irritates the skin minimally and works for 2-3 hours (maximum 6 hours). In repellents, it appears in concentrations up to 55 %.

Lavender

In a study, they tested 5 %, 10 % and 20 % concentration of essential oil. Essential lavender oil at a concentration of 5 % was sufficient for 40 minutes of protection against insects. While higher concentrations of essential oil were sufficient for 120 minutes of protection.

Peppermint

As a mosquito repellent a 1.5 % peppermint oil can be used, even in topical repellents. Peppermint essential oil also works against other insects. It works antifungal and antibacterial.

Other oils to repel insects within a natural way

Among them are citronella, eucalyptus, cinnamon, cloves, geranium, lavender, lemon, lemongrass, bergamot, red thyme, marjoram, spearmint and creeping (breckland) thyme.

Clove oil, creeping thyme oil and red thyme oil are the most effective repellents if used in the form of 3% essential oil. Polish thyme oil combined with citronella oil is an effective repellent combination that protects against insect bites up to 91 %.

Synergistic action

Oxford University tested basil and lantana extracts as repellents and found that they exhibit synergistic activity. In combination, they are longer effective against peak mosquitoes than individually. At the same time, the use of both together allows us to use lower concentrations of the extracts. They protect us from bites up to 120 or 150 minutes.

Safety warning for using synthetic repellents

In the study they used 20 % concentration of active ingredients, such as DEET and essential oils, in order to detect skin irritation and penetration. Pro-insect protection lasted up to a maximum of 8 hours. Repellents may contain substances that greatly irritate the eyes, so contact with eyes must be avoided. Some repellents can penetrate the skin. One of these is DEET, which can penetrate the skin up to 14 %. While essential oils can penetrate into the skin only up to 3 %. Essential oils also minimize skin irritation compared to DEET, which moderately irritates the skin.

Repellents should only be used on the exterior parts of the body.

  1. Don’t apply it to children under the age of 2 years.
  2. Never apply repellents on hands of children, because they are frequently in the contact with their mouth / eyes.
  3. Do not put in on your clothes.
  4. When we no longer need the repellent, we recommend showering with soap to remove the repellent from the skin as soon as possible, in order to avoid unwanted effects.
  5. If irritation occurs, the area must be rinsed with water and soap.
  6. The instructions must be followed closely.

If you can, avoid the hours when mosquitoes are active in order to prevent contact with them. If you want to go for a walk it is better to use repellents with essential oils, since they don’t irritate the skin so much and they also smell really nice.

You must have heard that hemp in cosmetics has positive effects on the skin. It is an increasingly popular ingredient for the treatment of skin diseases and the care of sensitive skin. Which parts of hemp are at all allowed for use in cosmetic products, what is CBD and what are cannabinoids, what effects does hemp in cosmetic products have on the skin?

Cannabidiol or CBD

First, we explain the basic terms. Cannabidiol is a phytocannabinoid that exhibits biological effects and acts against anxiety and nausea, and also has antitumour effects. Cannabidiol has no psychoactive effects. It has many positive effects on the skin, such as the ability to inhibit the formation of sebum and anti-inflammatory activity, as it inhibits immune responses to inflammation.

Cannabinoids

Cannabinoids were also proven to have anti-inflammatory and sebostatic (ability to inhibit the formation of sebum) properties. Cannabinoids are capable of inhibiting the maturation of keratinocytes, which is highly desirable in skin diseases, where the maturation of keratinocytes is abnormal, as in psoriasis and atopic dermatitis.

Endocannobinoids have psychotropic effects. THC is the only cannabinoid that is psychoactive, and there are still about 60 (according to some data, even 113) cannabinoids that do not show such effects.

Hemp seeds

In Chinese medicine and nutrition, hemp seeds have been used for more than 3000 years. Seeds are rich in vitamins A, C and E, and β-carotene, proteins (all essential amino acids), carbohydrates, fibers and minerals. The oil is obtained from seeds by cold pressing or by solvent extraction.

The seed also contain terpenoids and cannabidiol, which exhibit anti-inflammatory properties. The oil does not contain THC, unless it is present as an impurity. Concentration of THC in the oil depends on the cultivation itself and on the cleaning process. According to European legislation, the concentration of THC in oil must be less than 0,2%.

Fun Fact # 1: According to some data, Budha only ate cannabis seeds for 6 years. Seeds have an extremely nutritional value, thanks to proteins and unsaturated fatty acids.

Extract from cannabis seed

In the study on men,there was a cream containing 3% extract from hemp seed tested. After application of the cream with this extract, the secretion of sebum was significantly reduced. In men who had erythema, the redness decreased significantly.

What is hemp oil?

Marketing term for cannabis oil is the term “hempseed oil” so that it can be separated from cannabis used as a drug. Hemp oil is not obtained from leaves, but from cannabis seeds. This, of course, leads to the conclusion that hemp oil will not exhibit relaxation effects, as the seeds do not contain THC (tetrahydrocannabinol), except as mentioned above, as an impurity. THC is present only in cannabis leaves.

Fun Fact # 2: Cannabis with low THC value is estimated at $ 100-2000 million per year. What in the euro would mean about 90 – 1800 million euros. Crazy number, huh?

Composition of hemp oil

We have repeatedly mentioned the importance of oil composition. Hemp oil consists of all three of the most important fatty acids that act regenerative and / or antimicrobial. These fatty acids are very unstable because they contain double bonds that are highly reactive.

Linoleic acid – 57% (omega-6) is regenerative and anti-inflammatory

α-linolenic acid – 16% (omega-3) acts regeneratively

γ-linolenic acid – 3% (omega-6) acts anti-inflammatory

The ratio between linoleic and linolenic acid is 3: 1, which is the ideal ratio for dietary and cosmetic products. This oil can also serve as a natural source of antioxidants (vitamin E).

Atopic dermatitis and hemp?

Atopic skin has one disadvantage, namely, there is a defective action of δ-6-desaturase. It is responsible for the enzymatic conversion of linoleic acid into γ-linolenic. So, if desaturase does not work properly, we have an elevated level of linoleic acid, and the level of γ-linolenic acid is reduced. It is therefore desirable to use oils for the care of atopic skin, which also contain γ-linolenic acid, and thus add it itself because the skin itself does not produce it.

One of these oils is a hemp oil containing γ-linolenic acid. Due to the fatty acid composition, it helps to improve all skin diseases in which the skin barrier is weakened.

Studies also show the positive effects of cannabis on the skin

In Finland, a study was carried out in patients with atopic dermatitis, in which the test subjects orally used cold pressed hemp oil (30ml). They found that cold pressed hemp oil in an 8-week study, improved dryness of the skin and itching. The use of hemp oil reduced the use of topical medicines among test subjects. Olive oil was used as a control in which no such skin improvements were detected.

The endocannabinoid system in our skin

It is a biological system consisting of endocannabinoids. These are nonspecific lipid-binding carriers that bind to cannabinoid receptors and cannabinoid receptor proteins that are expressed in the central nervous system (including the brain) and peripheral nervous system. The endocannabinoid system is involved in the regulation of various physiological and other processes, including fertility, pregnancy, appetite, feeling of pain, mood and memory.

The effect on the endocannabinoid system would help to improve skin diseases such as psoriasis, atopic dermatitis, skin fibrosis, skin cancer, and itching.

What about hemp in cosmetic products?

In cosmetic products, oil from cannabis and hemp seed is allowed. Any extracts, tinctures and oils from flowers or fruits are prohibited. On the basis of the Regulation on cosmetic products no. 1223/2009 leaves and trunks are also prohibited. They belong to Annex II on cosmetic products where substances are prohibited in cosmetic products. On the list “Narcotics, natural and synthetic” we find cannabis resin, extracts and cannabis tinctures, which are also prohibited.

Sources:

Río, C. del, Millán, E., García, V., Appendino, G., DeMesa, J., & Muñoz, E. The endocannabinoid system of the skin. A potential approach for the treatment of skin disorders. Biochemical Pharmacology 2018. 

Singh, D., Fisher, J., Shagalov, D., Varma, A., & Siegel, D. M. Dangerous plants in dermatology: Legal and controlled. Clinics in Dermatology 2018; 36(3): 399–419.

Dhadwal, G., & Kirchhof, M. G. The Risks and Benefits of Cannabis in the Dermatology Clinic. Journal of Cutaneous Medicine and Surgery 2017; 22(2): 194–199.

Pacher P, Bátkai S, Kunos G. The endocannabinoid system as an emerging target of pharmacotherapy. Pharmacol Rev. 2006; 58(3): 389–462.

Montserrat-de la Paz, S., Marín-Aguilar, F., García-Giménez, M. D., & Fernández-Arche, M. A. Hemp (Cannabis sativa L.) Seed Oil: Analytical and Phytochemical Characterization of the Unsaponifiable Fraction. Journal of Agricultural and Food Chemistry 2014; 62(5): 1105–1110.