What is DHA in skincare?
DHA in skincare means dihydroxyacetone, a simple three-carbon sugar produced by fermenting glycerin. It is the active ingredient in essentially every self-tanner on the market, and has been used that way since the 1960s.
It should not be confused with docosahexaenoic acid, the omega-3 fatty acid that shares the abbreviation. Reviews of topical dihydroxyacetone cover its chemistry, performance and safety profile in sunless tanning products.
What skin concerns does DHA treat?
DHA does not treat a skin concern so much as change colour. It reacts with amino acids in the outermost dead skin cells through the Maillard reaction – the same browning chemistry as toast – producing pigments called melanoidins.
Because only surface cells are affected, the colour develops over two to four hours and fades in five to seven days as those cells shed. Crucially it offers almost no UV protection, so sunscreen is still required. Some research notes free-radical generation in treated skin, another reason to wear SPF over it.
What ingredients are best paired with DHA?
Exfoliate and moisturise dry areas – knees, elbows, ankles – before applying, since DHA grabs harder where skin is thicker and gives a patchy result otherwise.
Antioxidants such as vitamin C and E are sensible alongside it. Avoid applying it immediately after AHAs or retinoids, which speed up cell turnover and shorten the tan, and keep it away from freshly waxed or shaved skin. Take our Skin Quiz.
What is melasma?
Melasma is a common form of acquired hyperpigmentation that appears as symmetrical brown or greyish-brown patches, most often across the cheeks, forehead, upper lip and jawline. It develops when melanocytes – the pigment-producing cells in the skin – become overactive and deposit excess melanin into the epidermis, the dermis, or both.
It is far more common in women and in medium to deeper skin tones, and it behaves as a chronic, relapsing condition rather than a one-off mark – which is why management matters as much as treatment.
What causes melasma?
Three triggers dominate: ultraviolet and visible light exposure, hormonal change (pregnancy, oral contraceptives and hormone therapy – hence its nickname, the mask of pregnancy), and genetic predisposition.
Heat, visible light from sunlight and screens, inflammation from harsh products or aggressive procedures, and certain medications all make existing patches worse. Because the triggers are ongoing, melasma typically fades and returns rather than clearing permanently.
What ingredients are best for melasma?
Daily broad-spectrum sunscreen is non-negotiable, and a tinted mineral SPF containing iron oxides is best because it also screens the visible light that drives pigment production.
On top of that, the most evidence-backed actives are tranexamic acid, azelaic acid, niacinamide, vitamin C, alpha arbutin, kojic acid, liquorice root extract, retinoids and gentle alpha-hydroxy acids. Avoid harsh scrubs and strong heat, both of which can rebound the pigment. Take our Skin Quiz to build a routine around your skin tone and triggers.
