A healthy and beautifully tanned skin is the goal of many during the summer season, but it is not always easy to achieve. Let's start with the fact that each person has a different skin phototype, which determines the color of the tan and how quickly the skin will tan. Unfortunately, the sun's rays also have a negative effect, which accelerates skin photoaging and causes skin damage. Self-tanning is a great alternative when it comes to having healthy and tanned skin. In order to choose products that are safe for the skin and of high quality, we need to know several important aspects, so let's examine what self-tanning is and how to choose a safe product.
Self-tanning, this tan is obtained with special means that contain substances that promote pigmentation. Self-tanning is a great solution for those who want to protect their skin from photoaging and sun damage, as it is not based on harmful UV radiation. Self-tanning can come in many forms: lotions, creams, sprays, lotions, or even mists.
What are the substances that give a color tone to self-tanners?
Dihydroxyacetone (DHA) is one of the self-tanning ingredients used for decades. It is a sugar molecule naturally extracted from plants, commercially from alcohol. The DHA molecule reacts with the outer protein of the skin layer (keratin) and a Maillard chemical reaction occurs. During the reaction, a brown pigment is produced, which is retained on the stratum corneum. Compared to UV rays, which penetrate deep and affect all layers of the skin, damaging the skin structure, DHA only works on the surface of the skin.
The intensity of the tan color depends on the concentration of DHA in the product, which can vary from 2.5% to 10%. Too much of the substance causes unnatural orange tones, uneven skin coverage and drying of the skin. When choosing products containing DHA, it is important to pay attention to the fact that they also contain skin-nourishing substances (moisturizing, nourishing substances), because DHA has a tendency to dry the skin. Another important aspect is that DHA is quite sensitive to heat and light, so the shelf life of the product is quite short. The only safe way to use it is to open just before use.
Erythrulose is a natural keto sugar found in red raspberries. This substance is designed to eliminate the disadvantages of DHA, such as uneven tanning and the drying effect of the skin. This substance is more stable, so the shelf life of the product is significantly longer than that of a product that contains DHA. The erythrulose dye reaction with the skin is slow and gentle, resulting in a natural shade.
What determines the color produced by self-tanning?
In addition to the intensity of the color being determined by the concentration of the main self-tanning coloring agent, the pH of the skin as well as the pH of the product determines the tone of the skin after using the self-tanner. Alkaline skin pH caused by drying skin care products disrupts the chemical reactions of the skin's amino acids with DHA, resulting in a more yellow than brown shade.
In order to avoid a change in the pH of the skin, it is important to properly care for the skin 1-2 weeks before using self-tanning. Fragrances in body care products that contain a lot of drying alcohol should be avoided. Use products that nourish and moisturize the skin, use oil or gentle gel cleansers for washing. It is also important to avoid too hot water when washing, as it dries the skin, and to apply the cream on the skin within 4-5 minutes after showering.
DHA concentration in the products
Self-tanning cosmetics provide the effect of a light, light to dark tan. The intensity of the obtained color depends on the concentration of DHA in the product, which ranges from 2.5% to 10% in cosmetic products, but usually 5%. The products are divided into fair skin, medium dark and dark skin. This is an indication to the consumer of what concentration of DHA is used in the product and what shade to expect.
Are self-tanners safe?
In the past, dihydroxyacetone (DHA) was thought to be a non-toxic substance that only affects the outer stratum corneum of dead skin. However, more recent scientific sources show that about 11% of the DHA used penetrates into the living cells of the epidermis and dermis. A scientific study conducted on mouse cells found that DHA causes cellular DNA damage and can even induce apoptosis in living cells, causing them to die. During the scientific research, it was noticed that even after 24 hours dermal exposure to DHA significantly reduced cell proliferation, and epidermal thickening and cutaneous dermatitis were detected on the skin of laboratory animals after 21 days of 5% DHA.
- Increased production of free radicals
During the Maillard chemical reaction, the sugars in the DHA structure react with keratinocyte proteins, which cause the oxidation of sugar derivatives. During this oxidation, the pigments melanoidins are formed. Also during this process, chain reactions are formed that cause free radicals. Glycation of cellular DNA occurs, a process of reducing sugar content that can damage the nucleic acids of the skin's DNA. Advanced glycation end products (AGEs) also known as glycotoxins are formed. Free radicals and the glycation process damage cells and cause premature aging of the skin.
- Lower production of vitamin D
Regular use of self-tanners can reduce the body's production of vitamin D. According to this study, it is the melanoidin pigments created by DHA that inhibit vitamin D production. This can be a problem because vitamin D is needed for the overall immune system, bones, muscles and teeth.
- Skin irritation
For some people, self-tanner can even cause skin irritation and a weakened skin barrier. Regular consumption of DHA can cause contact dermatitis and damage to the top layer of the skin.
- Decreasing skin resistance to UV rays
Another risk is that topically applied products with 5% or higher DHA concentrations increase sun sensitivity after 24 hours. This can be a problem for people who use products with DHA on a daily basis. It has also been shown that people who use self-tanners with DHA are more prone to sunburn.
What substances should be avoided in self-tanners?
In the composition of self-tanning products, you can often find a considerable amount of fragrances to hide the unpleasant smell of the main coloring agent DHA. A large amount of fragrances irritates the skin and can cause allergies.
Another agent to avoid should be alcohol , which is used to give the impression of a fast-absorbing agent, but it does not absorb, but evaporates, irritating and drying the skin. It is not easy to find a product that does not contain alcohol, but it is not necessary to do so. It is worth knowing which alcohols are harmful and which are useful in cosmetic products.
Fatty alcohols are "good" alcohols
Fatty alcohols have a high molecular weight and have a creamy, oily or waxy consistency. Fatty alcohols act as binders, thickeners, emollients. They combine the parts of oil and water in the cosmetic product and keep the resulting emulsion stable, so that the cosmetic products do not become biphasic. These alcohols are used in products that soften, nourish hair or skin.
The most common fatty alcohols are:
- Lauryl Alcohol;
- Myristyl Alcohol;
- Cetearyl Alcohol;
- Stearyl Alcohol;
- Cetyl Alcohol;
- Behenyl Alcohol (mostly used as a preservative).
Alcohols to avoid are dehydrating alcohols. They are used in cosmetics due to their preservative and antiseptic properties. These alcohols are volatile and have the ability to evaporate. Drying alcohols cause drying of the skin, because when evaporating from the surface of the skin, they also evaporate water. The latter cause a lightness effect, but long-term use destroys the skin's protective layer, resulting in skin dehydration.
Alcohols that are most common in cosmetic products and should be avoided:
- Isopropyl alcohol;
- Ethyl alcohol;
- Alcohol denat;
More "good" and "bad" alcohols:
Chemical properties of DHA
One of the disadvantages of DHA is that the substance is less stable and is quite reactive with other chemicals, which makes DHA incompatible with some chemicals. Based on the chemical properties of DHA, the pH of products with DHA should be acidic (pH 4-5). In order to preserve DHA stable pH must not be lower than pH 3-4. For this reason, cosmetic products use non-ionized emulsifiers that thicken DHA-containing emulsions, such as hydroxyethyl cellulose, methyl cellulose, xanthan gum. DHA reacts with oxygen and nitrogen-containing substances, collagen, urea derivatives, amino acids and proteins, so these ingredients should not be used in long-term self-tanning cosmetics.
What can be done to make self-tanners less harmful to the skin?
1. Protect the skin from UV rays
After self-tanning, it is necessary to take a responsible approach to protection against UV rays, use a sunscreen with broad-spectrum UVA and UVB protection. You should choose sunscreens with titanium dioxide and zinc oxide, which not only protect, but also soothe the skin. Read more about sun protection here .
2. Use skin care products with antioxidants
The use of antioxidants before and after self-tanning neutralizes free radicals, prevents the breakdown of collagen, so that the skin does not lose firmness and elasticity.
Antioxidants: Vitamins C and E
Vitamins C and E help reduce the appearance of dark spots and fine lines on the skin. Vitamin C is known to fight the signs of aging by promoting the production of collagen, the protein responsible for making skin look taut and firm. Also, as an antioxidant, it helps protect skin cells from damage caused by free radicals during exposure to sunlight. Vitamin E also plays an essential role in fighting UV damage. It is an antioxidant that helps protect cells from oxidative stress. Vitamin E is also beneficial for the skin because it helps to moisturize the skin. It is important to remember that vitamin C should be used in the evening in the warm season and SPF protection should be used. The high concentration of polyphenols in green tea contributes to its anti-inflammatory properties. Thus, self-tanners containing green tea can reduce skin irritation and redness. Vitamin B2 in green tea also helps maintain collagen levels in the skin and acts as a powerful antioxidant.
3. Apply self-tanners in the evening
Because UV rays increase the production of free radicals on DHA-treated skin, it is best to avoid sunlight for the first few hours after using a self-tanner. Free radical production decreases after four hours. Using a self-tanner in the evening will allow the color to develop on its own without having to worry about layering sunscreen on top, and by morning, free radical damage will be much less likely.
4. Self-tanners with moisturizing components
Self-tanners with DHA dry out the skin. To avoid this, manufacturers produce the product as an emulsion with emulsifiers suitable for use on the skin surface, such as cetearyl glycoside, which strengthens the lipid structure of the skin and creates a protective barrier against moisture loss. It should also include moisturizing ingredients such as: hyaluronic acid, hemp seed oil extract, which contains all 21 amino acids necessary for healthy skin, black tea and aloe vera extract.
Can self-tanner be used permanently?
Self-tanners are a really great alternative for protecting your skin from UV rays, and in any case, it's healthier than tanning. When choosing a self-tanner, it is very important to choose a product that suits you, not to be too lazy to look into the composition of the product, because the product that is on the skin for several weeks should not dry out, irritate, but nourish the skin. It is also not advisable to abuse self-tanners, because the means weaken the formation of vitamin D caused by radiation, which is of great importance for the body's overall immunity. Let's take care of not only the beauty of our skin, but also the health of our skin!
Our selection of self-tanners can be found here.
The article was prepared by carolinashop.lt beautician Uršulė Grakauskaitė.