The dihydroxyacetone or DHA is the main component of self-tanning products. Whether synthetic or plant-based, this sugar browns the skin by reacting with the amino acids present in the horny layer. Are there any dangers associated with its use in topical application? Does this compound have any contraindications?
The hazards of Dihydroxyacetone (DHA).
Summary
Published on August 7, 2024, by Maylis, Chemical Engineer — 5 min of reading
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A few reminders about DHA: how does this molecule act on the skin?
Dihydroxyacetone (DHA) is a triose, that is, a simple sugar composed of 3 carbon atoms. This molecule, soluble in water and ethanol but insoluble in oil, can be of synthetic or plant origin. Naturally derived DHA is typically obtained from a biotechnological process that involves the stages of fermentation and bacterial bioconversion of glycerol extracted from plants such as beetroot, corn or even rapeseed. The resulting DHA is a crystalline white powder. Incorporated into certain skin care products, it provides an artificial tan and gives a sun-kissed complexion 2 to 6 hours after its application. This effect results from the Maillard reaction: the DHA reacts with the amino acids in the corneal layer of the skin to produce melanoidins, which are responsible for the brown colour.
Are there any dangers associated with the use of DHA?
When applied to the skin, DHA is considered non-toxic and safe. No scientific study has proven that DHA penetrates the skin's protective barriers. It is not contraindicated for pregnant women and is suitable for all skin types. In self-tanning products, DHA is regulated at a maximum concentration of 10%.
The SCCS (Scientific Committee on Consumer Safety) has stated that DHA present in self-tanning products poses no health risks to the consumer at a maximum concentration of 10%.
It is important to note, however, that inhaling or ingesting a DHA-based self-tanner is strongly advised against. Indeed, this can cause asthma as well as DNA damage and increased cancer risks.
Are there any side effects associated with the use of DHA?
A self-tanner containing DHA can cause a 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.
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 humectants such as glycerine and/or sugar derivatives..To combat this potentially drying effect, ensure you moisturise your skin daily, morning and evening, both on the face and body.Theface moisturising creamwith 9 ingredients is enriched with hyaluronic acid and organic 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.
Note : As with any new treatment, it is recommended to perform a patch test in the crook of the elbow before applying a DHA-based self-tanner to the face and/or body. This allows for the detection of any potential intolerances to the treatment or the specific molecule in question.
DHA does not protect against UV rays.
It is important to clarify that melanoidin is different from melanin. The production of melanoidin occurs only on the surface, which means it is eliminated once the skin cells are renewed. Unlike melanin, this molecule has no protective power against the sun's UV rays. Always remember to protect your skin using a broad-spectrum sunscreen to avoid the harmful effects of UV rays.
Sources:
KOCHEVAR I. E. & al. Factors affecting sunless tanning with dihydroxyacetone. British Journal of Dermatology (2003).
Opinion on Dihydroxyacetone. Scientific Committee on Consumer Safety (2010).
