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.
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.
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 ingredient||Properties||Side 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|
|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|
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).
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.
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.