The dihydroxyacetone or DHA is a sugar that provides a tanned complexion to the skin without the need for sun exposure. It is the main active ingredient in self-tanning products. It is generally combined with another sugar: erythrulose. Discover its mode of action for a natural tanned complexion, as well as the various treatments that contain it.
Dihydroxyacetone, for a natural sun-kissed complexion.
Summary
Published on August 7, 2024, by Maylis, Chemical Engineer — 4 min of reading
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What is Dihydroxyacetone and how does it act on the skin?
The dihydroxyacetone (DHA) is a ketotriose, meaning it is composed of three carbon atoms, with a carbonyl group in the middle of the chain. Present in many self-tanning products, this sugar can be of plant or synthetic origin. When it is plant-derived, it is obtained through the bioconversion of glycerol found in corn, sugarcane, rapeseed, beetroot, palm oil, and so on.
Upon contact with the skin, DHA triggers a chemical reaction resulting from the glycation of amino acids contained in corneocytes (cells of the horny layer). This reaction produces melanoidins, heterogeneous polymers responsible for the brown colouration of the skin. The pigmentation appears within 6 to 12 hours following the application of the self-tanning product. However, this colour gradually fades to completely disappear in 5 to 7 days.
This phenomenon is explained by the frequent renewal of the stratum corneum (natural process of desquamation). Having no effect on melanocytes, this artificial tan provides no protection against UV rays. The use of a sunscreen that is suitable is therefore recommended for sun exposure.
In which skincare products can one find dihydroxyacetone?
When applied topically, DHA is regulated to a maximum concentration of 10%, but it is generally present at 3 to 8%.As previously mentioned, it provides a tanned complexion by reacting with the amino acids in the stratum corneum. It thus acts as an active ingredient in self-tanning products. There are different galenic forms: milks, creams, serums, gels...
At Typology, we have formulated two self-tanning treatments, providing colour and radiance to the complexion. Our self-tanning serum contains 10% DHA combined with erythrulose for a natural finish. It also includes carob pulp extract to prolong the tan. This treatment enhances the complexion just 12 hours after the first application for a progressive effect. For the body, we offer our self-tanning gel, enriched with 6% DHA, and also containing aloe vera, which has a moisturising action. It also gradually colours the skin and gives it a light and natural tan.
Note : DHA is also aningredient in hair dye products. It works in a similar way to how it does on skin cells, that is, through a browning reaction called the Maillard reaction or glycation. The colours obtained using products rich in DHA are generally temporary. However, they allow for colouring without damaging the hair fibres. As a result, the hair maintains its shine and health. It should be noted that the concentration of DHA allowed in hair dyes cannot exceed 6.25%
Are there any risks associated with the use of DHA on the skin?
The SCCS (Scientific Committee on Consumer Safety) has stated that DHA found in self-tanning products poses no health risks to the consumer at a maximum concentration of 10%. Furthermore, no scientific study has proven that DHA penetrates the skin's protective barriers. It is not contraindicated for pregnant women.
However, a self-tanning product containing DHA can cause irritation if applied to sensitive areas of the body. That's why all body parts covered with mucous membranes should be free from self-tanner.
