How spray tan really works: The science behind DHA (Dihydroxyacetone)

The difference between a good spray tan professional and an excellent spray tan professional - they'll want to educate you.

A spray tan professional shouldn't just show up and spray. As well as their bag of tools and tricks and a honed technique, they should know their products inside out. The ingredients, the different undertones, the consistency of the mist, how it interacts with your skin, what's happening during the development stage and how your skin turns brown.

At the heart of every spray tan solution is a molecule called DHA (Dihydroxyacetone). But what exactly is it, and how does it turn your skin that sun-kissed shade without a single ray of UV light?

What is DHA?

DHA is a sugar compound that’s usually derived from natural sources such as sugar beets or sugar cane. It’s been used in cosmetics since the 1960s and is approved by regulatory bodies like the FDA and EU for external use in tanning products.

How DHA reacts with your skin?

When DHA is applied onto your skin, it reacts with the amino acids (the building blocks of proteins) in the very top layer of your skin - the stratum corneum. This reaction is called the Maillard reaction, the same chemical process that makes bread turn golden in the toaster. The result? Pigmented compounds called melanoidins are formed - this gives the skin its bronzed appearance. As the reaction only takes place on the outer layer of dead skin cells, the colour gradually fades as your skin naturally sheds. This is why a spray tan typically lasts 7 days before needing a top-up.

What else is in a professional spray tan formula?

DHA is the star of the show, but it’s not working alone. Most professional tanning solutions include:

• Erythrulose - another sugar that works like DHA but develops more slowly, helping to create a longer-lasting, more even colour.

• Moisturisers & hydrators - like aloe vera, glycerin, or hyaluronic acid to keep skin soft and prevent patchiness.

• Bronzers - cosmetic tints that give an instant glow while the DHA develops underneath (these wash off with your first shower).

• Antioxidants & skin-loving extras - such as vitamins A, E, B5, B12, CoQ10 green tea extract, or botanical oils, which support skin health and improve application.

• Fragrance & colour correctors – some solutions are designed to suit different skin undertones (olive, golden, or violet bases) for a more natural result.

Is it safe?

Yes! DHA is a clever, skin-safe ingredient that gives you a beautiful tan without the harmful effects of UV exposure. Combined with hydrating and skin-friendly ingredients in professional formulas, spray tanning is not only about looking bronzed but also about nourishing your skin.

So, the next time you step out with that golden glow, you’ll know it’s not magic - it’s science.