Have you ever showered with a shower gel that gives such silky feeling that you don’t want to ever leave? Well, silicones are responsible for this feeling. Also silicones can be found in most primers. They are ˝guilty˝ for the smooth effect and we can’t blame them. #sorrynotsorry

What are silicones ?

Silicones are synthetic organic polymers of silicon. They can form silicones, silicates, silanes, or siloxanes. These can connect to larger molecules, which are normally flexible.

  Chemical structure State of matter
1. Silicone oils (dimethicones, cyclomethicone…) Liquids
2. Silicone waxes (alyildimethicones) Resins
3. Silicone emulsifiers (silicone polyether) Elastomers (dimethicones)

Approximately 85% of all silicones in cosmetic products are classified as silicone oils. That’s why we’ll give them a little more attention.

Silicone oils


Dimethicones are waterproof ingredients, that distribute well over surfaces and are inert (they don’t react with other compounds). In one of the studies, more than 60 different dimethicones were observed to see which one is most common in cosmetic products. The most commonly found are dimethicone/vinyl dimethicone crospolymer (in 457 cosmetic products) and dimethicone crospolymer, which was present in 442 products.


Cyclomethycones are volatile compounds, but they don’t leave a cold feeling while evaporating as ethanol does. They are odorless and non-toxic. Usually they are used as solvents or carrier systems for other silicones. With their incorporation into lipsticks, we can prolong their persistence.

Silicone waxes


Alkyldimethicones improve the compatibility of ingredients with oils and increase the stability of cosmetic products containing silicones. They work as moisturizers as well. They are used in many cosmetic products such as lipsticks, creams and lotions. They are very welcomed in suncreens since they are able to increase their effectivness.

When can we use silicones?

Silicones are safe and compatible (aren’t complicated and can get used to the new environment quickly). They are excellent ointments and lubricants, antifoams, emulsifiers, emollients and surfactants. Almost everything, right? But recently they are not that ˝in˝ anymore, since almost every package has a ˝without silicones˝ inscription.

Where can we use them?

Silicones are very common in decorative cosmetics and in skin care products. They are also found in products for children and products for sensitive skin, because they don’t irritate the skin. They are also suitable for application to deeper skin layers. Their origin isn’t animal so they are also suitable for vegans.

1. Hair: accelerated drying, increased shine, easier combing, regeneration

2. Give a good sensory feeling on the skin

3. Moisturizing (formation of a film that can beathe)

4. Skin protection (waterproof)

5. Cleaning ability (silicone powder – the ability to absorb lipophilic substances, including sebum)

6. Increase the effectiveness of active ingredients

7. Matting effect (for oily skin products, since silicones aren’t comedogenic)

8. Adhesion of pigments (used in primers under our make-up)

What are their advantages?

Silicones can get very well distributed and well smeared. They are surface-active (surfactants) substances that are colorless, tastless and odorless. Absence of color, taste and smell is very important in the formulation of cosmetics. They are inactive, temperaturely and chemically stable (they don’t interact with other substances).

Studies show that silicones are very safe for the consumer. They belong to the “Clean Beauty” substances. Clean Beauty is a platform where you can find safe products, they can be made of natural or synthetic materials. The point is, they are safe for the user.

Myths about silicones

“Silicones are toxic to nature because they rinse into rivers and seas.”

Health Canada has concluded that cyclomethicone (a type of silicone) has a low or no probability of environmental pollution and there is no necesity for any restrictions about the use of this substance. Very volatile silicones quickly evaporate and degrade in the air under the influence of the sun. Smaller quantities that remain in solid or liquid state are hydrolysed.

“We inhale silicones inhale and can be loaded in the lungs.”

Approximately 95-99% of the particles in sprays are bigger than 10 μm. According to the study, the particles inhabited by mistake are located and remain in the nasal cavity. They don’t go anywhere, regardless of the amount of silicones we inhale. So the chances of inhaling silicones, which can get and stay in the lungs is equal to almost 0.

“Silicones can clogg the pores.”

Silicones as substances aren’t occlusive (we still know what that means, right?), So they can’t clog the pores. They help to protect our epidermis and are also allowing our barrier to “breathe”. There are no reports proving that silicones irritate our skin, they actually do all the contrary, the feeling they leave is very ligh and soft.

However, due to the whole chaos, they are looking for alternative forms. Substances that are recently replacing silicones are olive oil derivatives, argan oil derivatives, coconut derivatives, alternatives to silicone elastomers, wheat sprouts.

In one study, however, it was confirmed that silicones pass the skin barrier and are loaded into epidermis. It’s expected to have negative effects on the epidermis, which we can see as a reduction of it. However, the whole study is imprecise, as they didn’t specify which parameters they took into consideration, so it’s difficult to be sure about the relevancy of this study.


If you are still afraid that the use of cosmetic products with silicone will clogg the pores, don’t worry, it won’t. Whether silicone compounds cross the skin barrier or not we know that such large compounds don’t cross neither healthy or damaged skin. Silicones have many advantages, even though they aren’t natural.

We already opened the shorts season, when travelling in Sicily and Morroco. And by this we opened the season of hairless legs. Hairs have their purpose to protect us from mechanical and thermal effects of the environment. But nowadays because of the impacts of the society and aesthetical reasons we remove the hair with several different depilation and epilation techniques.

Let’s get to know our hairs!

On our body there are two types of hair: fluffy and terminal. Terminal hairs are longer (more than 1mm), thicker, more pigmented, usually there is one hair for pilosebaceous unit and have longer life cycle. Fluffy hairs are shorter, thinner, there are more hairs growing in a pilosebaceous unit, are non pigmented and have a shorter life cycle.

Phases of hair growth

Hairs go through 3 different phases. First is anagen phase or phase of growth, that lasts approximately 6-8 years and depends on gender, age and health. Second is catagen phase or phase of transition – in this phase the growth in hair bulb starts shutting down and slowly stops. Last is the telogen phase is which the hair dies off, the hair bulb moves towards the surface and the hair falls out. When the last phase elapses, new cycle begins.

Photography: Neja Stojnič

Methods of hair removal

We know depilation and epilation techniques. And many people use this two terms wrong. With the term depilation we always think off removing hair with the wax, but this is wrong.

Depilation methods remove hairs without the effect on a hair bulb, the effect of depilation lasts around two weeks. Under the term depilation we count shaving and chemical depilation.

Epilation methods remove hair, including the bulb, the effect lasts around 6-8 weeks. Under term epilation we count waxing, pulling, laser methods and electrolysis.

Physical methods shaving, waxing, pulling hairs with tweezers, use of abrasives
Chemical methods chemical and enzymatic depilation


We will not discuss this for long, like the effect of the shaving doesn’t last long (maybe 3 days). Shaving is the most popular method, because it’s fast, simple, cheap and the least painful. Hairs are removed only from the skin surface.

Shaving accelerates hair growth and makes them thicker.

Photography: Neja Stojnić


Waxing counts as a epilation method. The effect last around 6-8 weeks.Waxing does not accelerate hair growth. For this methods hairs need to be at least 3mm long. It is unsuitable for diabetics and patients with vascular diseases. It can also cause some side effects like folliculitis, hyperpigmentation and scars.

Ingredients in waxing cosmetic products are usually: resin, bees wax, paraffinum, camphor, local anesthetics and ingredients with antibacterial effect.

Hot waxing is the process, where we heat up the wax and then apply it on the skin so it surrounds the hairs so they become a part of the wax. We remove the wax in the opposite direction of the hair growth. In cold waxing there is no need to heat up the wax.

Chemical methods of hair removal

Hair removing runs with chemical compounds and enzymes. The procedure happens without pain and it’s effects are visible for 2 weeks. Chemical compound penetrates in the hair cortex, where the reduction of disulphide bond in keratin happens. Simply, this means that the bonds that hold the hair together splits and this causes the hair to fall out. Hairs are removed on the skin surface or little underneath.

Active ingredients for hair removal
Active ingredientPropertiesSide effects
Sulfide (barium sulfide)– most effective
– strong unpleasant smell
Toxic for the skin, hair grows back into the skin
Sulfite– less irritation and absence of the strong smell
– ineffective
Mercaptans– methyl, butyl, benzyl-mercaptane have very strong smell
– less smell from polar mercaptans (tiolactic acid, tioglycolic acid) – slower but safer
Skin irritation, inflammation, chemical burns, scars
Photography: Neja Stojnić

Cosmetic products for depilation based on thioglycolates

First ever patented depilatory creams were based on thioglycolates and until today they still present a standard for chemical depilation. Most commonly used it calcium thioglycolate in combination with calcium hydroxide. A reversible reaction happens between hair keratin and alkaline thioglycolate. Depilation effect happens after 5-15min, pH rises above 10. These compounds are safe in concentrations up to 15%, show low systemic toxicity and are stable (in concentrations between 2,5-5%).

Side effects may be: skin irritation, inflammation, chemical burns and scars.

Laser hair removal

Discovery that lasers unspecifically destroy hair follicles was made more than 60 years ago. Laser enables selective photothermolysis – hair removal without damaging the surrounding tissue.

How does a laser work?

Exact certain wavelength of light and the duration of laser pulse leads to thermal damage of target tissue, that contains a chromophore. Melanin in hair follicle absorbs the laser light. Laser energy in the form of a light transforms into heat, that causes selective destruction of a hair follicle.

With this procedure the final destruction can be done to the hairs, that are in the moment of procedure in growth phase (5-15% of all body hairs), that’s why this procedure needs to be repeated (5-8 repetitions).

Nd:YAG laser

This laser can have a continuous source of light or pulse with wavelength of 1064nm. Melanin badly absorbs light with wavelength as high as this, that’s why this laser is ineffectual for permanent hair removal. Fast warming causes photomechanical damage to melanocytes in a hair bulb, wherein there is no damage done to the hair follicle. This is the safest and most efficient laser for dark skin (type IV). It only causes the delay of hair growth not the permanent removal.

Effectiveness of laser hair removal

One treatment only delays the hair growth for a short period of time. Before the treatment hairs need to be removed with shaving. While doing the treatments with the laser you should avoid exposure to the sun. Laser is the most effective on light skin with dark hairs, and not so effective with light or blonde hairs.

Fotografija: Neja Stojnić

IPL technology

IPL regulates the spectre of light with wavelength from 550nm to 1200nm with filters and so adjusts considering the skin phototype and hair color. More treatments lead to permanent hair removal. At IPL technology the light effects all the skin surface, not only hair follicles like the laser does. Because of this fact the risk of skin damage is higher with IPL. Effectiveness of IPL compared to laser is lower, because the energy is more scattered and is not concentrated just on the hair.

Nanoparticles are one of the latest threats to humankind. Almost. Certainly not in cosmetics. Nanoparticles don’t exist from yesterday, they have been here for quite some time. Only science, that studies them – nanotechnology is relatively new.

What are nanoparticles?

Nanoparticles are small units of material, that is smaller than 100nm. We know that nanometer is 10⁻⁹ right? Nanoparticles can come from a different origin: natural (desert dust), unintentionally produced (burning out biomass and fossil fuel), engineer (sunscreens and other cosmetics, textile).

Photography: Neja Stojnić

Why do we even use nanoparticles?

Nanoparticles exhibit new properties and functions of already known materials. This properties are very different than the properties from the same ingredients, but bigger order of size. Not only in cosmetics, but also in food technology and medicine they show a lot of advantages.

  • they stabilize and protect ingredients and extend the time of usage (fatty acids in oil, vitamins and antioxidants)
  • they affect  solubility and speed of solution of the ingredients
  • better activity on the skin
  • higher effectiveness and tolerance of UV filters
  • delivering cosmetic active ingredients in deeper layers of the skin

But everyone says, that nanoparticles are bad,..

Every good invention has a bad side, right? Nanoparticles can be toxic. Toxicity can be a consequence of damaging effects of decomposed products from nanoparticles. Physical properties of nano sized particles (big surface, charge), regardless the chemism of the products that compose nanoparticles, can be a reason for toxicity as well. Nanoparticles show unique physical-chemical properties because of their size. They can be more chemically reactive and can express higher biological activity.

Photography: Neja Stojnić
The connection between nanoparticles and unwanted effects

In the last few years the exposure to nanoparticles has risen because of development of different techonologies. Scientists have figured out, that this leads to a lot of unwanted effects on your health system. Connection was made between nanoparticles in the environment and unwanted effects of respiratory tract and cardiovascular system.

Special physical-chemical properties of nanomaterials lead to forming reactive oxygen species in cells. Reactive oxygen species (ROS) cause oxidative stress. Cells react to this kind of stress with inflammation. Research on rodents had shown that empty nanoparticles have a much higher inflammation effect on the unit of mass than bigger particles with the same chemism.

Inhalation of nanoparticles leads to loading in the lungs, they can also enter the bloodstream and brains. That’s why their use is forbidden in aerosols.

Now before you panic, close your computer and throw all of your sunscreens with nanoparticles away

Nanoparticles don’t work like that when applied to the skin. Our epidermis provides effective protection from effects of the environment. They can pass through the cells, hair follicles or sweat glands. But they don’t pass healthy skin. Damaged skin is another story, in this case the particles can pass the skin, but under what conditions remains unknown.

Why are mineral UV filters in sunscreens in nano size?

Mineral filters in their normal size (200-400nm for zinc oxide and 150-300nm for titanium dioxide) disperse really badly and because of that the application is difficult. They reflect and scatter the light and that causes an unwanted white layer on the skin surface. With the help of nanotechnology we are able to reduce the size of the parcticles under 100nm. With doing that we achieve easier application and transparency.

Photography: Neja Stojnić

Do nanoparticles cross the skin – main subject of scientists

There are a lot of arguments between scientists whether nano sized particles pass the skin barrier and what are the effects of penetrating into the deeper layers. Some studies prove them passing the skin and their toxic effects on the cells, while others disprove this theory.

There are many differences depending on the sort of the vehicle in which we include nanoparticles. Researches had shown that nanoparticles in mineral oil did not pass the skin, while the ones included in O/W emulsion (oil in water – usual for all the creams) did penetrate. Penetration was much higher in the area with a lot of hairs, which shows the penetration through the pores and hair glands.

The smaller the particles, the bigger the chance that they will penetrate the skin. There is a big difference between a particle that is 2nm big and particle that is 50nm big. As we mentioned before, the smaller the particles, the bigger the chance that their properties will change.

Does a regulative on cosmetic field protect us?

We’ll be honest, not really. Cosmetic producers are not obligated to tell what size of  nanoparticles are included in their products. They are obligated to write ‘’NANO’’ next to the filter that is in nano size, but whether this means particles 2nm or 100nm large no one knows, except them.

They represent a big progress in cosmetic industry

Usage of nanometer delivery vehicles is the future. Until now all the cosmetic products contained highly effective ingredients, that manufacturers bragged about. But whether this ingredient will achieve the wanted target in the skin was another thing. Only molecules smaller than 500Da can penetrate in the skin. And if we include a peptide with a molecular mass of 4000Da in our products, it will most certainly not penetrate in the skin. Nano delivery vehicles enable reducing these big molecules into smaller ones, so they can be included to the systems that will reach the target area. This delivery systems are liposomes, dendrimers, solid lipid nanoparticles,..

What is your opinion on nanoparticles in cosmetics?

Surely there was a time when you wanted a beautiful bronze skin without having to roast under the sun. Self-tanning products are a good solution. That may be because of today’s world where tanned skin represents an ideal. But is that really a healthy ideal?

Nowadays, the majority of people are already aware that UV rays are responsible for aging and increased chances for skin cancer. In some countries the sun doesn’t shine as often as for example in Barcelona. That’s why the needs of the consumers have shifted from sun creams to tanning lotions.

What determines our skin colour?

In our skin, there are 2 different types of melanin pigment: eumelanin (brown pigment) and pheomelanin (orange pigment), which are responsible for the colour of our skin.

What even are self-tanning products?

Self-tanning products are products that help us achieve beautiful bronze skin without sunbathing. Such products do NOT contain protection against UV rays. Keep in mind that products that provide UV protection need to be applied additionally.

In laboratory in college we made a self-tanning product (photo is posted with approval of the author)

Which active ingredients help us to achieve apparent tanned skin?

Dihydroxyacetone (DHA)

DHA is the most known active ingredient that causes skin coloration. It’s formed in our body, so therefore it is harmless. DHA is present in almost every self-tanning product on the market. It is also the only colour supplement used in self-tanning products authorized by the FDA (Food and Drug Administration).

How and when did they even realize that the DHA can work as a self-tanning ingredient?

In 1950s, at the American Paediatric Hospital. They performed an oral DHA test in children who previously had problems with proper glycogen storage (diabetes). Because some children experienced regurgitation (some medicines have been spit out), the DHA accidentally got to the surface of the skin. Where it affected the skin, the skin darkened. That is how it has been found that DHA acts as a tanning agent. By accident of course.

The first self-tanning products came to the market in 1977 (according to some data already in 1959). Since then, demands for such products have grown. The biggest problem of DHA was and still is, the unevenness of the application and the unnatural appearance of the colour, the tone is also dark orange, which is not very tasty to see.

How much time after application can I expect effects?

DHA is usually present in self-tanning lotions in concentrations from 3 to 5%. The change in skin tone is usually seen 1 hour after the application, but requires 8-24 hours to fully develop and lasts for 5-7 days.

The number of applications depends on the location and composition of the skin (the face needs more frequent deposits than arms and legs for example).

Fotografija: Neja Stojnić
Weak points of DHA in self-tanning products

The biggest problem of DHA is the yellow/orange skin tone that it causes and which looks very unnatural. DHA also heavily drains our skin. It’s sensitive to strong acids and bases, increased temperature, the presence of microorganisms and is stable at pH 4-6. It is not appropriate for pregnant women, asthmatics and those who have an allergy to self-tanning products. Regular and long-term use is not recommended. It mustn’t get in touch with your lips, eyes or mucous membranes. It can irritate the skin, but studies say that in moderation DHA is safe.


L-erythrulose is another active tanning ingredient. The skin looks much more natural after the application of the product and also coloration is more even. That’s because the reaction in the skin is much slower (the colouring occurs within 2 days) and is also less intense (in comparison with DHA). It is found in self-tanning products in concentrations from 1 to 3%. It doesn’t dry out and doesn’t irritate the skin, nor does it cause allergic reactions.

There are also vegetable dyes that improve the self-tanning process. They are based on henna and walnut, which are not so persistent and therefore less common in cosmetic products.

Otherwise, the best compromise is the combination of DHA and erythrulose. Why? Because using both helps to get fast coloration and more natural tan (erythrulose). That’s exactly what we want, don’t we?

How do self-tanning ingredients work?

DHA and erythrulose work on the same principle. They react with amino groups, peptides and proteins in the corneous layer of the epidermis. The reaction occurs on the surface of the skin and doesn’t penetrate deeper, therefore the colour is only persistent for relatively short amount of time. The self-tanning reaction may be influenced by several factors or skin characteristics (type, firmness, dryness …). But the colour fades because of the natural peeling of the skin.

How to get a nicer tan?

In the table, we collected data on how certain substances in self-tanning products work (what’s their effect). There are different results if we are talking about dihydroxyacetone or erythrulose. All these ingredients beautify the tan and ˝kill˝ the red or yellow tone.

Humectants (up to 5%) High impact in yellow and red High impact in yellow
Emolients High impact in yellow, less in red High impact in red and less in yellow
UV filters (up to 2%) High impact in yellow and red TiO2 – red High impact in yellow TiO2 – yellow
Vitamines (up to 5%) Low impact in yellow and red Retinyl palmitate – the most intensive colour High impact in yellow, less in red. Ascorbic acid – red
Thickeners High impact in the yellow, low impact in red Low impact in yellow, no impact in red
Active ingredients Low impact in yellow and red Low impact in yellow

In addition to all of these, the final effects of the self-tanning product are also affected by aminoacid derivatives and antioxidants in combination with active ingredients.

After application, it is recomended not to expose to the sun for some time; the skin shouldn’t be wiped with a towel. Skin shouldn’t come in contact with water.

How about you? Do you use self-tanning products or do you rather sunbathe? Or maybe the third option, you are rather pale, like we are.

How little does it take to get a new idea. An e-mail from a Slovenian cosmetic company called Koko cosmetics caused some brainstorming. We had decided to create a new category on our blog: Slovenian cosmetics. Why? We just want people to realize that there are a lot of small companies, that create wonderful cosmetic products.

Natural cosmetics and certificates

What makes natural cosmetics different from conventional? Ingredients, ofcourse! Properties of extracts, hydrolates and oil are the ones that make natural cosmetics so special. But cosmetic manufacturers are not limited by any legislation and law, so the manufacturer himself decides whether he will work according standards that are defined by certificates. On the other hand the manufacturer can just advertise his cosmetics as natural and doesn’t work according to standards.

On the field of natural cosmetics exist numerous certificates that are very different from one another. Even in Slovenia a cosmetic brand can recieve a ‘’natural cosmetics’’ certificate by an institute called Kon-cert that prescribe, that cosmetic products don’t contain disputable ingredients.

Tonic and cleansing milk

Why is goats milk as an ingredient so desired in cosmetics?

The data from history reveals that Cleopatra took baths in goats milk. So it’s obviously something on this milk. Goats milk has a few special properties, because of which it shows good effects on the skin.

  1. It doesn’t cause inflammation or allergic reactions (cows milk can cause allergic reactions) – very suitable for sensitive skin
  2. Contains lactic acid, which is a alpha hidroxy acid (AHA) – AHA stimulate skin proliferation, increase skin moisture and work as a keratolytic (they accelerate exfoliation)
  3. Has a proper ratio between omega-6 : omega-3 = 5:1 fatty acids – omega-6 and omega-3 fatty acids show a really good effect on the skin, they help to restore the skin barrier especially on the individuals with skin diseases
  4. It’s rich with retinoids (vitamin A) – retinoids normalize keratinization and posess anti-ageing properties (concentrations in goats milk are too smal to show that properties)
Cream for sensitive skin

How about cannabis oil?

Cannabis oil is extracted from a plant named Cannabis sativa. Oil is rich with canabinoids, which are attributed with good effects on the skin. Cannabis oil is rich with omega-6 and omega-3 unsaturated fatty acids.

  1. Regulates skin inflammation – it exhibits anti-inflammatory properties with effect on immune system cells
  2. Can reduce pain and itchiness – stimulation of CBD2 in keratinocytes causes secretion of analgetic opioid peptydes, that reduce pain
  3. Regulates sebum secretion – with an effect on hair follicles it reduces sebum secretion from glands

Because of it’s anti-inflammatory properties it is recommended to people that suffer from skin disease’s such as atopic dermatitis, psoriasis and others. Because of it’s possibility to regulate sebum secretion and anti-inflammatory properties it is also good for acne-prone skin.

What is Koko cosmetics?

Koko cosmetics is a brand that creates 100% natural products. It combines unique properties of goat milk and Cannabis oil in all of their face creams. This two ingredients are enriched with addition of hydrolates, that are very good humectants.

Hydration cream Koko
How did their products do on a test?

For the testing we received: cleansing face milk, cleansing facial tonic and two face creams, one for sensitive skin named Madame Chamomile and one moisturizing cream named Lady Rose. To be honest none of us really likes the taste and smell of goats milk so we were concerned about the smell of the products. But let us tell you that yes, maybe creams have a little specific smell, but the other products smell like flower hydrolates.

All the products are packed in a quality, air-free packaging. This is so important when the products are natural, because the manufacturers are limited with preservative choices and that’s why this products are more likely to get a microbiological contamination.

We both have skin, that is quite hard to satisfy, since we get little pimples if the products does not fit our skin needs. The products did a really good job on a test, since we did not break out (yay!). Both of the creams are really moisturizing and the moisturizing cream does a really good job on greasy skin as well.

How did Koko products perform in a laboratory test?

This is where it gets interesting. We decided to test Koko cosmetics cream Madame Chamomile for sensitive skin. With the test we wanted to see whether the application on the cream on the skin will rise skin hydration. All of the measurements were made with a Corneometer – this is an equipment that measures hydration of upper skin levels.

Relative values of skin hydration are stated in arbitrare units and these units can not be equated with the percent of relative skin hydration.

very dry skin< 30 arbitrare units
dry skin30 – 45 arbitrare units
normal skin> 45 arbitrare units

We measured skin hydration before applying Koko face cream on colleague’s dry skin. After the measurement we applied the cream on the face for a half an hour to let is soak into the skin. After half hour we measured skin hydration again. This were the test results:

AreaSkin hydration before applying cream (in arbitrare units)Skin hydration after applying cream
(in arbitrare units)

Skin hydration has risen after the application of Koko cosmetic product. We have to realize that the measurement’s weren’t made in the ideal environment, so they can deviate a little in a positivne or negative way. But after all the skin hydration did rise quite a lot.

Measurement with Corneometer
We came across another beautiful Slovenian brand

Koko cosmetics turned out to be a wonderful brand, that performed good at home and laboratory tests. Ingredients in Koko products are just brilliant.

What are peptides? How did they even come to the idea to use them in cosmetics? In this post you will learn everything about peptides, their positive properties and about challenges that manufacturers face when they are creating and including peptides in cosmetics.

The fact is that we are ageing and so is our skin, the most obvious signs of ageing are seen on face. Wrinkles, redness, hyperpigmentation start to appear. There is also a decrease in collagen fibers and skin moisture. Facial expressions cause wrinkles too. Smokers tend to have more wrinkles around the mouth area, while people who laugh a lot tend to have move wrinkles around their eyes.

What are peptides?

Peptides are compounds that consist of shorter amino acid sequences. There are two types of compounds oligopeptides, that are short peptides and polypeptides that consist of longer sequences. Very long amino acid sequences are typical for proteins (like collagen). Peptides differ from each other by physiological functions, some are peptide hormones, others are antimicrobal,..

We gain peptides with partial hydrolysis from proteins. But here we bump in our first problem. Unfortunately in this process manufacturers have no control how long the peptide will turn out (how many amino acids will it consist of), what chemical structure will it have and whether the chemical composition will be the same in every synthesis. Consequently we don’t know the mechanism of action and how long will the compound last.

Photography: Neja Stojnić
Synthetic peptides

They are better, because they have explicit chemical composition. Consequently there are less mistakes when manufacturing, their production is also safer.

Why would we even use peptides in cosmetics?

Because they affect cell receptors and receptors participate in physiological answer.

  1. Stimuation of collagen synthesis and aid in firmer and thicker skin – ideal ingredient in anti-ageing cosmetics
  2. Stimulation⁄braking of melanin synthesis – useful in tanning and lightening products
  3. Anti Inflammatory effect – useful for cosmetics that soothe the skin
Peptides influence homeostase of skin barrier

Applied topically, peptides slow down skin ageing, studies say. On the face there is visible reduce of fine lines, the skin firmness is higher. Peptides take care of skin barrier homeostase.

Examples of peptides used in cosmetics

  • Acetyl hexapeptide-8  two studies that used this peptide topically showed reduce in deepness of wrinkles
  • Trifluoroacetyl tripeptide-2 – expresses lifting effect, stimulates collagen production, brakes matrix metalloproteinase and reduces looseness of the skin
  • Palmitoleil tripeptide-7 – establishes cell communication and slows down the ageing process. It stops proinflammatory interleukins 6 and 8 (they cause inflammation). Skin inflammation happens for a reason, every time this happens there are consequences on the skin.

In study there was a serum with peptides tested on several women with mildly photoaged skin. None of the testee’s reported about irritation. Women noticed reduced redness in comparison with placebo serum. After 14 days of using the serum with peptides there was an evident change, especially in the under eye area. There was reduce in smiling wrinkles noticed as well. Testee’s reported about much better general look of the skin like smoothness, softness and skin glow.

Photography: Neja Stojnić

Why don’t we find peptides in every skin care product?

  1. Questionable solubility and stability – we don’t know whether our peptide will be durable in the formulation and whether it will keep its biological activity
  2. Does it penetrate the skin? For the best would it be if we packed them in delivery systems, but this is not as simple as it sounds and we don’t know if they will reach the target area
  3. Quite expensive – this is quite a problem since we usually don’t want to spend more than 30 EUR for a product
  4. There are small concentrations needed – which is good right? But there is a bigger chance that the peptide will not last for a long enough time to reach to target area. They will probably decompose (will still have a hydration effect because of the amino acids, but will not stimulate collagen production)
  5. Safety of this compounds – still questionable, since we don’t know what compounds it  forms if it connects with other compounds – risk for unwanted effects
Photography: Neja Stojnić

With peptides we target cells that are dermis or subcutis. But as we already know, our skin is designed in a way that ingredients hardly pass upper layers of the skin. Consequently it is hard for peptides to reach deeper layers of the skin and get to the target area.

What can we conclude?

We can use modified peptides to get better stability and effects on the skin (moisture, firmness, softness) and hair. If we mix them with silicones we get ingredients for hair care that increase hair glow and moisture.

We think peptides are an amazing ingredient in cosmetic products. We have to investigate further to find more stable forms and good delivery systems that will enable peptides to travel to the target areas.

Cellulite, THE problem of almost every woman! According to researchers, more than 80% of all women have cellulite! Well, if we all have it, why do we even care? We are beautiful just the way we are!

Cellulite is a condition where fat is typically distributed in the form of dents and bulges. They occur in areas of the body with hypodermic fat tissue (thighs and buttocks). Cellulite affects mostly women and is not caused by obesity.

Why are men born under a lucky star?

First they have one product for bathing, hair washing and car washing. In addition they don’t even have cellulite. Is this even fair? But for real now…

Due to differences in the natural distribution of the fat tissue and the connective tissue, cellulite in male skin is very rare. The fact is that they have less fat ventricles than women and their connective tissue is more diagonally organized (women’s connective tissue is more rectangular).

Photography: Neja Stojnić
The role of estrogen in the production of cellulite

Estrogen is a female hormone that plays an important role in the development of the cellulite. Estrogen stimulates the production of an enzyme collagenase that causes decomposition of collagen fibers. In places where the collagen fibers are weakened, fat cells or adipocytes gain more space and consequently new fat cells can be formed.

How can we recognize cellulite?

Orange skin is typical for cellulite. If we touch the skin firmly, we can feel the differences in the flexibility of the fat tissue, micro nodes and tissue thickening and also irregular skin temperature.

Photography: Neja Stojnić

Cellulite develops in stages

Phase 1

The skin is still smooth and firm. Cellulite is only shown when pressing the skin. Adipocyte deformation occurs, edema begins to appear due to increased capillary permeability. This stage is still reversible.

Phase 2

Cellulite is noticeable while standing. The flow is impeded in the lymph and blood vessels, the capillary permeability increases and edema occurs. The connective tissue is getting weaker. This stage is still reversible.

Phase 3

The skin looks like an orange peel while standing or sitting. The tissue is loose. Adipocytes (fat cells) fuse into larger aggregates, which are surrounded by inflexible collagen and consequently micro nodes and tissue thickenings are formed. The skin loses its firmness.

Phase 4

At this stage cellular metabolism and protein production weaken. Skin regeneration is affected. The skin is very loose. Micro nods are visible (size up to 20mm).

Why is cellulite formed?

All the causes of cellulite production are only hypotheses, which are not fully proven yet.

The diet impact – Asian women have less cellulite than Caucasian women. Why? Because the cow’s milk we normally drink is rich in estrogen. But generally speaking there are still more than 80% of women that have problems with it.

-Genetic influences on fat distribution – Usually the daughter will have cellulite at the same places as her mother, regardless of diet and estrogen stimulation, but it also depends on the amount of fat in the body.

Vascular insufficiency – Hearing this for the first time? well, this means that the weakening of the vessels in the dermis leads to fluid retention and worst appearance of cellulite.

Too much fat tissue – women with more body fat have more cellulite and even by reducing weight they can’t get rid of it.

The appearance of cellulite may get worse with bad nutrition, too little activity, obesity, hereditary predispositions, vein diseases and many other reasons.

Photography: Nel Čater

Can we control cellulite?

By physical activity we increase the metabolism. Consequently blood circulation increases which is the reason for less visible cellulite. By massaging and lymphatic drainage we enable better blood flow. Also, many waste products from the lymph eliminated. Cold / hot showers increase blood flow and tighten the tissue.

What about anticellulite cosmetics?

Sincerely, a cosmetic product that eliminates cellulite doesn’t exist! However we have a lot of ingredients that improve the appearance of the affected parts. The cosmetic ingredients for limiting cellulite are differentiated by the mechanism: increasing blood circulation or microcirculation, reducing lipogenesis and increasing lipolysis, establishment of normal structure of dermis and subcutis (retinoids) and substances that prevent the formation of radicals (antioxidants).

Ingredients that increase blood circulation

These compounds are responsible for reducing the permeability of the capillaries, improving the tonus of veins, improving venous and lymphatic drainage and reducing edema. They are also anti-inflammatory. So, the smaller the capillary transitivity,

The smaller is edema the better is blood circulation. Consequently cellulite will be less visible. What “wizards” classify to this group? Ginkgo (Gingko biloba), ivy (Hedera helix), Butcher’s broom (Ruscus aculeatus), horse chestnut (Aescelus hippocastaneum), pentoxifylline, papaya and red grapes.

Photography: Neja Stojnić
Compounds that reduce lipogenesis and increase lipolysis

Firstly we should differentiate these expressions. Lipogenesis is a fat forming process, while lipolysis is a fat degradating process. That’s what we want, right? This group includes: caffeine, aminophylline, theophylline and theobromine (ingredients of green tea).

Photography: Neja Stojnić
There are also some physical and some invasive methods possible for cellulite removal.

Radiofrequency and liposuction work by using rays of energy. Heating the problematic parts, leads to degradation of adipocytes. Cavitation is based on ultrasonic waves. Lymphatic drainage is a procedure for stimulating the lymphatic vascular system.


Almost all women deal with cellulite, which can be in the first or fourth stage but that is not important at all. What’s important then?  Respecting our bodies and not being ashamed of having a dent or two. Keep calm! It presents a ˝problem˝ for more than 80% of women. But that is not the reason to not rock some shorts in the summer!

Always when you look at a cosmetic product, ingredients must be written somewhere. The description of these ingredients is based on the INCI list. If INCI isn’t available the name can be based on the chemical name of the ingredient.

Ingredients of cosmetic products must be listed on the decreasing order of weight. But only if their content in the product is bigger than 1%. If it’s smaller, the ingredients can be listed by pure chance.

But we cannot use all the ingredients randomly. There is a Regulation on cosmetic products. This Regulation consists of:

1. Report on the safety of the cosmetic product

2. Annex of prohibited substances (Annex II)

3. Annex with restricted substances: pigments, preservatives, UV filters (Annexes III – VI)

The substances we pay special attention to are: ingredients with restrictions, nanomaterials and CMR substances (hormonal interrupter). Why? Because this is the only way to ensure that cosmetic products are safe for the consumer. We have a lot to say about nanomaterials.

Photography: Neja Stojnić

We want to clear something out. Animal testing has been banned since 2013. When writing the Safety Report on Cosmetic Products, researches done before 2013 and tested on animals, can be used. But there cannot be any new animal testing. Instead of animal testing, alternative methods have been introduced, which are slowly replacing animal testing. But the truth is that all this is prohibited in the EU. If we order a product from another continent where these restrictions are different, no one can guarantee us that the product has not been tested on animals. Because it can’t be controlled.

From theory to practice

We will now look at some examples. Almost all preservatives that are allowed in cosmetic products have certain limitations. We know what the preservatives are, right?

So, the easiest way to “understand” INCI is to know the restrictions of a particular substance. The exact percentage of a substance doesn’t have to be given. But what we want to know is at least the approximation of that percentage.

Let’s look at the structure of the cream containing vitamin C. If we buy a cream containing vitamin C, we want some effect, right? But if the percentage is too low, there will be no effect.

Aqua, Isoamyl P-Methoxycinnamate, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Aloe barbadensis leaf juice, Glycerin, Gyceryl Stearate, Phenoxyethanol, Acrylates / C10-30 Alkyl Acrylate Crosspolymer, Sodium Stearoyl Glutamate, 3-0-Ethyl Ascorbic Acid, Xanthan Gum, Tocopherol , Sodium hydroxide, Hexyl cinnamal, Linalool, Limonene, CI 15510, Citronellol, Benzyl Salicylate, Potassium Sorbate, Sodium Benzoate, Geraniol, Sodium Chloride, Sodium Sulfate, CI, Fragrance, Sodium Citrate, Ethylhexylglycerine, Sodium Hyaluronate, Panthenol, Crystalline Ethylenediamine Disuccinate 14700

So, we can find a preservative in the INCI list. In our case, this is phenoxyethanol, the concentration of which is limited to max 1% in the Regulation. As you can see, vitamin C (ethyl ascorbic acid) is listed after phenoxyethanol, which means that this product contains less than 1% of vitamin C.

Aqua, Isoamyl P-Methoxycinnamate, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Aloe barbadensis leaf juice, Glycerin, 3-0-Ethyl Ascorbic Acid, Gyceryl Stearate, Phenoxyethanol, Acrylates / C10-30 Alkyl Acrylate Crosspolymer, Sodium Stearoyl Glutamate, Xanthan Gum, Tocopherol , Sodium hydroxide, Hexyl cinnamal, Linalool, Limonene, CI 15510, Citronellol, Benzyl Salicylate, Potassium Sorbate, Sodium Benzoate, Geraniol, Sodium Chloride, Sodium Sulfate, CI, Fragrance, Sodium Citrate, Ethylhexylglycerine, Sodium Hyaluronate, Panthenol, Crystalline Ethylenediamine Disuccinate 14700

Well, this looks a bit better. In this case, we can look at other substances with restrictions. For example UV filters. Methoxy cinnamate and triazine are limited to a maximum concentration of 10%. Phenoxyethanol is found after vitamin C (ascorbic acid). That usually means that this product contains more vitamin C than in the example above, but not necessarily. Since there is no rule dictating whether there need to be written the exact concentrations of the ingredients, we can only assume about the real concentrations in the products.

Some more useful web pages, if you ever find yourself in a dead end

Most verifying website for substances in cosmetic products is called CosIng. What can we find on this site?

1. All the names of the substances (chemical, INCI, other possible names)

2. Restrictions, if there are any (there is an attachment, where all restrictions are written)

3. What’s the function of the substance in the products

4. The SCCS opinion (we have already discussed this, in the case of parabens, which have been said to have carcinogenic affects – the committee has checked all the studies and limited the percentage so that the use is safe now)

SCCS = group (committee) of independent experts writing opinions on ˝problematic˝ substances.

There is also Rapex, where we can find all products containing any prohibited substances. If the product is in the Rapex system, it’s immediately removed from the market. The company may change product’s composition (they replace the problematic substance with another) and then the product has a ˝second try˝ on the market.

Yes, in cosmetic industry it’s all limited just approximately. But still, we can manage this ˝chaos˝ more or less. It’s not the easiest, but it’s the most effective. Hopefully, the next time you will be experts on checking the composition of your cosmetic products and you will be able to decide whether you are being misleaded or not.

We’ve already gone through basics about UV rays, protection against UV rays and everyday use of sunscreen. Now it’s time to take a look in the world of compounds that protect us from UV rays – UV filters.

There are two types of UV filters

Organic or chemical and inorganic or physical UV filters. Physical filters scatter and reflect UV rays, while chemical filters absorb them. Physical filters leave a white residue (unless they are nano size), while chemical filters spread quite smoothly.

Sunscreens are usually a mixture of different chemical and physical filters, because with combining them we achieve a broad spectrum protection.

There are even more UV filters then we mentioned in a previous post, so we asked members of a Slovenian Facebook group Ljubim kozmetike to mark the most common filters in their sunscreens. We are going to describe 4 most common ones.

Organic UV filters

Data from studies shows, that organic filters are present in most sunscreens on the market. The most common organic filter is Ethylhexyl methoxycinnamate, since it is present in 80% of all sunscreens. Chemical filters easily absorb in the skin and reach blood circulation. Consequently they can load in different tissues, liver and brain.

Ethylhexyl methoxycinnamate

Oktyl metoxycinnamate (OMC) is a UVB filter known as 2-ethylhexyl-4-metoxycinnamate. As a compound it is allowed for usage in cosmetic products in United States and Europe in concentrations between 7.5-10%. Lots of studies suggest that OMC in an endocrine disruptor, because it can affect excretion of hormones.

After applying of cream with 10% concentration of OMC on the whole body (40g), the filter was absorbed in the skin and was later found in urine and blood. But if we take the highest measured concentration, the complete concentration in 4.7L of blood was only 0.002%.

The positive side of this filter is that it does not irritate the skin and does not cause sensibilisation.

Ethylhexyl salicylate or oktyl salicylate

It’s a organic UVB filter, that absorbs the UV rays. It is allowed for usage in cosmetic products in concentrations up to 5%. This is a filter with relatively good safety profile. Ethylhexyl salicylate possesses an ability to stabilize other photolabile (sensitive to light) UV filters and make them longer lasting. Quite a guy, ha?

This filter has a really low toxic profile. It does not cause irritation or sensibilization, it is not phototoxic and does not cause foto-allergies.

Inorganic UV filters

Inorganic filters used in sunscreens usually contain metal oxide particles, for example titanium dioxide and zinc oxide. These two can be used in concentrations up do 25%, but are usually contained in lower concentration – between 5-10%.

Chemical filters are still dominant in sun-protection products, but the number of products containing only physical filters is rising. One of the reasons why is the fact that they offer a broad spectrum protection – TiO₂ is more successful protection from UVB range, while ZnO is more successful at protection from UVA and UVB1 rays (the protection for UVB range is lower). Using these both filters together provides a broad spectrum protection. Another positive side of using physical filters is absence of irritation and limited skin penetration.

Zinc oxide

Dermal absorption is the main route of entrance for ZnO nanoparticles in our system. Most studies showed that ZnO particles don’t penetrate in deeper layers of the skin. Penetration is significantly higher when the skin barrier is damaged.

Titanium dioxide

Titanium dioxide is commonly used as a white pigment in colors, plastic and paper and as an additive in food. Nanoparticles of TiO₂ are used because of the capability to absorb the UV light in sunscreen products. TiO₂ particles have very low toxicity.

Nanoparticles of TiO₂ can be used in sunscreen products in concentrations up to 25%. Studies show that particles of this filter don’t penetrate healthy or damaged skin. In human keratinocytes it exhibited almost no cytotoxicity, which suggest a very small toxic potential on the skin level.

Exposure to UV filters

We are most exposed to UV filters in a dermal way. Suggested application of sunscreen is 2mg/cm² skin, so that we would reach the protection factor listed on the product. This means we would have to use the whole 40g cream to protect the whole body. At this amount of product, the maximum penetration would be 5% for some organic UV filters. Studies show that amount of product applied is much lower than suggested (less than half). So if we apply a product with SPF 50, the real protection will be probably 25 or less.

UV filters offer a protection from erythema, actinic keratosis and carcinoma. There is also data that sunscreens block normal synthesis of vitamin D and that they act as endocrine disruptors. But in normal usage this is not the case.

What can we conclude?

Usage of UV filters is questionable from aspect of safety. More and more studies show the link between bigger usage of sunscreen products and phenomenon of hormonal and growth disorders. At this point you need to realize that in studies they work with much higher concentrations than allowed. With cosmetic products it is impossible to come in touch with such high concentrations. But we can’t just ignore what the studies say, because side effects can occur within sensitive population. Effects of being exposed to low doses of UV filters for a long period of time are pretty much unknown. Scientists should investigate further and try to find safer compounds to protect us from UV rays.

Sunscreen is essential for preventing skin diseases and premature aging. In conclusion: sunscreen should be used in every season. However, experts started to warn about the importance of protection against UV, but that happened only a few years ago.

There are several types of electromagnetic radiation and one of them is UV radiation. Ultraviolet radiation consists of 3 wavelengths: UVA rays (emitting a wavelength from 320 to 400nm and aren’t absorbed by the ozone), UVB rays (the wavelength from 290 to 320nm, partially absorbed by ozone) and UVC rays (are stopped by ozone) -> well, what’s still left from ozone.

UV radiation has some beneficial effects, such as vitamin D synthesis. It also has a positive effects on the treatment of dermatological problems (acne, psoriasis), bone and joint disorders and childhood diseases. However, there are more negative effects (role in pathogenesis of skin cancer, photo-aging and photo-immunosuppression) than positive.

Acute effectsImmediate pigmentation, photosensibilisationErythema, edema, pigment darkening, thicker epidermis, synthesis of vitamin D
Chronic effectsPhoto-aging, immunotoxicityPhotocarcinogenesis, immunotoxicity

UVA rays

UVA rays represent the largest part of solar radiation. They stimulate the formation of reactive oxygen species or ROS. We’ve already been writing about it in blogs (Vitamin C and After 25th, we begin to grow old). UVA rays increase the number of inflammatory cells and reduce the activity of Langerhans cells, which are the first line of defense of our immune system.

UVB rays

UVB radiation causes sunburn. It represents about 18% of total solar radiation and it’s 50-100x stronger than UVA radiation. Our DNA molecules absorb UVB light very well, which can lead to mutation and carcinogenesis. They can damage biomolecules (proteins, lipids and DNA molecules).

UV rays don’t rest!

A few days ago, we’ve asked on Instagram story some questions about your habits regarding to sunscreens and their usage.

57% use the sunscreen only on the beach

56% prefer using sunscreen with a very high protection factor (50, 50+)

69% apply sunscreen several times a day

22% avoids nanoparticles in sunscreens

It’s a bit worrying that more than half of you use sunscreen only at the beach. It’s true that in winter the sun is significantly weaker comparing to summer, but this doesn’t necessarily mean there are no UV rays. In winter while it’s snowing it’s even more likely to get sunburned, because UV rays reflects from snow (white colour reflects sun rays). Despite the fact that there are clouds, who says UV rays can’t pass these clouds to get to us? Again, not so much, but they pass through. Have you ever heard of a friend who went hiking ant the weather was cloudy and came home as red as a beet? Because we have! So this means that UV rays exists even on a cloudy day.

Why is re-application necessary?

Probably, the ones who had answered that apply sunscreen only once, are asking themselves what the hell? You have applied the cream, okay. So you don’t sweat or touch your face? Consequently, by touching and sweating you remove the cream. Also, UV filters stop working after a certain amount of time, meaning they no longer have the effect of protection.

Sun protection products

The main purpose of sunscreens is to protect the skin against the harmful effects of UV radiation. But in order to achieve this effect, it takes more than just choosing the right UV filter in the appropriate concentration. One of the important things is also technological formulation and other ingredients which can support the effect of UV filter or can decompose it.

There is currently a flood of sunscreen products on the market. The SPFs are from 1-50 +. There are products with low protection (SPF 6-10), medium protection (SPF 15, 20, 25), high protection (SPF 30, 50) and very high protection (50+). According to European standards, UVA protection must represent at least 1/3 of the declared SPF.

Recently, we have seen the SPF mark on almost all face products, whether it’s decorative or nourishing. It is especially popular that UV filters are added to the powders, BB and CC creams.

What’s the problem of foundation with SPF15?

If you didn’t just come from the Stone Age, you probably know that for a SPF written on packaging, the application must be 2mg / cm². You probably don’t know how much of sunscreen that is. For a face it is supposed to be used 2 full fingers of cream. We are not 100% sure, but somewhere we’ve found that 70kg man has to use almost the whole sunscreen in order to achieve the SPF protection written on the packaging. Is this even possible? Not really.

Because of the incorrect or insufficient amount (usually 0.8 mg/cm²) of the sunscreen, the actual SPF on our skin is only 20 to 50% of SPF declared on the packaging. So, when using foundation with SPF15, we usually apply a pump or two. This means the actual SPF on the skin is probably barely 3, if not less.

SPF 30 vs. SPF 50

I think that most of us, who have been more or less introduced to the protection against UV rays, know this graph.

This graph shows us that with the protection factor 30, we achieve approximately 95% of protection against UVB rays. With a protection factor of 50, approximately 96.5% of protection. Experts are arguing whether this 1.5% makes a big difference. We must be aware of the amount of UV filters that must be incorporated into the product with SPF 50 comparing to SPF 30. This increased quantity may be unfavorable for people with photosensitivity disorders. If you don’t have them, it’s up to you, if you want to use higher or lower SPF. Keep in mind that you are likely to apply less product and the actual protection is lower.

Types of UV filters

Currently, two types of UV filters are in use, physical and chemical, both of them minimize the previously listed effects of exposure to UV radiation.

Physical or inorganic filters disperse and reflect UV rays while chemical or organic filters absorb them. More and more studies assess the role of these compounds in developmental and endocrine abnormalities, which have been demonstrated in animal and human studies.

Organic UV-absorbing filters are divided into: PABA derivates (PABA, ethylhexyldimethyl PABA), cinnamic acid derivates (ethylhexylmethoxycinnamate, octylmethoxycinnamate), salicylic acid derivates (homosalate), octocrylene, triazine derivates (ethylhexyl triazone), benzophenone derivates (oxybenzone BP-3), sulisobenzone) and dibenzoylmethane derivates.

Among the physical UV filters that reflect and disperse UV rays are zinc oxide and titanium dioxide. Sunscreens are mostly a mixture of several organic and physical UV filters, because with the combination we achieve broad spectrum protection.