Obtained through biotechnology or synthetic means, dihydroxyacetone is a colouring agent found in certain hair care and self-tanning products. Here, you will find all the information you need to know about this molecule.
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Everything you need to know about Dihydroxyacetone (DHA).
Summary
- Dihydroxyacetone (DHA): What is it?
- How does DHA act on the skin?
- How does DHA act on the hair?
- Are there any risks associated with the use of DHA on the skin?
- Sources
Published April 7, 2022,
updated on August 7, 2024,
by
Maylis, Chemical Engineer
—
7 min read
Dihydroxyacetone (DHA): What is it?
The dihydroxyacetone (DHA) is a carbohydrate monomer composed of three carbon atoms, also known as a triose, with the raw formula C3H6O3. This molecule, soluble in water and ethanol but insoluble in oil, can be of synthetic or plant origin. The dihydroxyacetone of natural origin is generally derived from a biotechnological process which involves the steps of fermentation and bacterial bioconversion of glycerol extracted from plants such as rapeseed, corn or beetroot.
How does DHA act on the skin?
DHA is currently themain active ingredient in self-tanning products. When applied to the skin, this tanning agent reacts with the amine functions carried by the amino acids present in the dead cells of the stratum corneum to form pigments, known as melanoidins. The browning effect on the skin results from this reaction, known as the Maillard reaction. The skin 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 exfoliation process). Therefore, this method of tanning without sun exposure does not trigger the production of melanin and thus has no protective effect against UV radiation. Always remember to protect your skin with a broad-spectrum sunscreen to avoid the harmful effects of UV rays.
It's worth noting, in the 60s, DHA was not favoured due to the unnatural orange hue it left on the skin. It only became popular in the 80s when combined witherythrulose, it then provided a much more uniform and natural tan. Theerythruloseis also a compound obtained through biotechnology. This natural sugar is present in plant cells, such as raspberries or beetroot in particular. This erythrulose/DHA synergy is indeed present in our self-tanning serum, as well as in our self-tanning gel. These treatments enhance the complexion within 12 hours after the first application for a progressive effect.
How does DHA act on the hair?
DHA is also an ingredient in hair dye. On hair fibres, it acts in a similar way to how it does on skin cells, that is, through the browning reaction, known as the Maillard reaction. The colours obtained using products rich in DHA are generally temporary. However, they allow for colouring without damaging the hair fibres. Indeed, this type of treatment only acts on the surface of the hair, without deteriorating its structure. The hair thus retains 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?
In self-tanning products, DHA is regulated at a maximum concentration of 10%, but it is typically present at levels of 3 to 8%. The SCCS (Scientific Committee on Consumer Safety) has stated that the DHA found in self-tanning products does not pose any health risks to the consumer at a maximum concentration of 10%. Furthermore,no scientific study has proven thatDHA penetrates the skin's protective barriers. It is not contraindicated for pregnant women.
On the other hand, 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. Similarly, inhalation and ingestion of this type of product are not recommended. Indeed, this can cause asthma as well as DNA damage and cancer risks.
Furthermore, DHA can dry out the skin and increase its sensitivity to the sun. It's worth noting that this characteristic is often counterbalanced in self-tanning formulas by the presence of humectant compounds such as glycerine and/or sugar derivatives..To combat this potentially drying effect, ensure you hydrate your skin daily, morning and evening, both on the face and body.Theface moisturising creamwith 9 ingredients is enriched with hyaluronic acid and coconut oil ; it's a minimalist formula that hydrates and nourishes the epidermis. Its light and non-greasy texture is suitable for dry, normal and combination skin, even sensitive ones. For the body, opt for thebody moisturising creamwith 10 ingredients, which hydrates all skin types, even sensitive ones.
Sources:
KOCHEVAR I. E. & al. Factors affecting sunless tanning with dihydroxyacetone. British Journal of Dermatology (2003).
Scientific Committee on Consumer Safety. Opinion on dihydroxyacetone (2010).
CIRIMINNA R. & al. Dihydroxyacetone: an updated insight into a significant bioproduct. ChemistryOpen (2018).
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