Content

Introduction

Tanning obtained by applying cosmetics such as self-tanning products to the skin is a "practical alternative" to sun exposure, tanning lamps and possible damage caused by ultraviolet rays (contained in solar radiation).

They are commercially available as creams and lotions, in spray form or in the form of soaked wipes that everyone can apply themselves. More recently aqueous spray solutions composed of one substance, the dihydroxyacetone (DHA), are used in self-tanning booths in beauty salons.

There are also self-tanners in the form of tablets or capsules based on canthaxanthin (a yellow-orange dye of natural origin, known by the acronym E161g, widely used as a feed additive for its effectiveness in the red pigmentation of the feathers of canaries or other birds, in intensifying the red color of egg yolks and the skin of chickens for fattening), or beta-carotene, with known antioxidant properties.

To avoid risks it is necessary to understand the mechanism of action of these products, in order to know how to use them correctly.

How they work

Generally, self-tanners contain one substance, the dihydroxyacetone (known as DHA), which is its main ingredient or active ingredient. It is a carbohydrate, or simple sugar, like glucose but does not have the properties of DHA.

Only small sugars, such as DHA, which has only 3 carbon atoms, anderythrulose, which has 4 and which is often contained in self-tanners mixed with DHA, react quickly with the proteins of the cells of the most superficial layer of the skin (stratum corneum). Thanks to this reaction, a few hours after applying a self-tanner on the skin, a temporary brown color is generated which simulates that of a natural tan.

This is not a real tan, because self-tanning creams do not stimulate the production of melanin from the deeper layers of the skin, but simply "color" the surface. The reaction is the same that occurs between proteins and sugars in food cooking processes, for example when browning vegetables or toasting bread.

Since the coloring is given by the modification of a protein after a chemical reaction, the coloring is not eliminated by washing and disappears only when the surface layer of the 'colored' skin is removed and replaced with a new one (about a week). The color obtained is a little different from that of the tan and tends more towards orange because the products that are formed are different from melanin. The different products, however, can give different colors.

On the market there are also the so-called bronzer, make-up products such as face powders and moisturizers, which dye the skin but vanish when you wash.

Most self-tanners do not contain sunscreens, but even if there were, their effectiveness would still be limited to a couple of hours. It should therefore be borne in mind that these products do not offer any protection from ultraviolet rays and that for all outdoor activities it is essential to protect yourself with products that shield against solar radiation.

Safety

Topically applied self-tanners are generally considered an "alternative to" sun exposure. There Food and Drug Administration (FDA), the US drug control authority, approved the dihydroxyacetone for external use (application to the skin). The Scientific Committee for Consumer Safety (SCCS) of the European Commission, which deals with the evaluation of the ingredients of cosmetic products, also ruled in 2010 confirming the safety of DHA contained up to a percentage of 10% in creams and lotions and also in relation to the possibility of inhaling self-tanning cosmetic products in spray packages and self-tanning booths, where DHA is used in a concentration between 8 and 14%.

However, it is recommended not to spread the product on the mucous membranes of the mouth, nose or areas around the eyes, to avoid undesirable effects, and to strictly follow, as for all other cosmetics, the instructions on the labels. In fact, in the composition of self-tanning creams and sprays there are many other chemicals that could be irritating to the most sensitive skin. For example, tanning wipes, due to their ease of application and the homogeneous result they allow, are widely used. However, they contain alcohol-based substances useful to increase fluidity and ease of application, but which could be more irritating than the cream or spray and give dryness to the skin.

The use in pregnancy does not cause problems for the development of the fetus. However, an allergic reaction of the mother to self-tanning products is possible, since the hormonal changes that occur during pregnancy can increase the degree of sensitivity of the skin. It is therefore advisable to test a baby. amount of product on a "limited area of ​​the body to see if any reactions develop.

Self-tanners in pills, containing large amounts of canthaxanthin, they are not as safe.Side effects can cause skin rashes, hepatitis and damage to the retina (retinopathy) and are not recommended during pregnancy.

Useful tips for application

The application of products in cream, lotion or with wipes requires some precautions:

  • use disposable gloves, to avoid darkening the palms of your hands
  • wear protective eyewear, ear plugs and cocoa butter on the lips, while applying a spray self-tanner
  • avoid using the spray in confined spaces or without adequate ventilation
  • exfoliate the skin (peeling) before applying the product, in order to eliminate dead cells from the epidermis; focus in particular on the areas where the skin is generally thicker, such as knees, elbows and ankles, and then dry
  • massage the product into the skin with circular movements, to avoid creating uneven tan and apply it evenly on the various parts of the body (arms, legs and chest)
  • remove excess from knees, elbows and ankles, areas where the product tends to be absorbed more using a wet wipe
  • be careful in the presence of skin blemishes and / or freckles, the self-tanner, coloring them, makes the spots even more evident
  • wait for the product to dry before dressing, wait at least 10 minutes, prefer non-tight clothing and try to limit sweating

It is also important to remember that:

  • protect yourself with products containing sunscreens before exposing yourself to the sun and for all outdoor activities, because the effect due to self-tanners does not protect against damage from UV radiation
  • limit yourself to using the product on intact skin and do not spread the product on the mucous membranes of the mouth, nose or areas around the eyes, to avoid unwanted effects
  • follow the instructions on the product labels, as with all other cosmetics
  • use only known and safe commercial channels to avoid the purchase of uncontrolled or counterfeit products

Bibliography

Mayo Clinic. Sunless tanning: What you need to know (English)

NHS. Is it safe to use fake tan during pregnancy? (English)

Scientific Committee on Consumer Safety (SCCS). Opinion on dihydroxyacetone. 2010 (English)

In-depth link

Italian Society of Medical, Surgical, Aesthetic Dermatology and Sexually Transmitted Diseases (SIDeMaST). Last minute tan? Let's paint with the spray tan (safe)

Italian Society of Aesthetic Medicine (SIME). Glossary of Aesthetic Medicine

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