BHT

When a formula has to stay fresh instead of turning into a sad, smelly science experiment, BHT often gets called in. Its meaning is butylated hydroxytoluene, which sounds like a chemical from a very serious lab coat convention, but in cosmetics it mainly works as an antioxidant and preservative helper. In plain English, it slows down the oxidation of oils and other sensitive ingredients, so your cream, lipstick, or perfume doesn’t go off before you’ve had a chance to finish it. That’s the basic how does BHT work story: it donates a hydrogen atom to free radicals, which helps interrupt the chain reaction that causes rancidity.

So what are the benefits of BHT on skin? Mostly, it helps the product you’re applying stay stable and effective. It’s not there to treat your skin the way niacinamide or glycerin might, and the health benefits of BHT you might see online usually refer to its role in preventing oxidation, not to some direct skin-transforming magic. In cosmetics, the concentrations are generally tiny, often around 0.01% to 0.1%, and the Cosmetic Ingredient Review has considered it safe in the small amounts typically used in leave-on and rinse-off products. Studies on skin absorption have found very limited penetration, which is one reason it’s been allowed in cosmetics for decades.

You’ll also see BHT in products beyond skincare, because it helps formulas stay stable in everything from lotions to fragrance oils. That’s why people ask about how to use BHT in perfume: the answer is usually that it’s blended in by the manufacturer, not something you add at home. The same goes for “how to use BHT for skin” or “how to take BHT capsules” searches online: those are usually about dietary supplements or other non-cosmetic uses, not what this ingredient is doing in your moisturizer. And if you’ve ever wondered about the “best BHT,” the real answer is the one used at the right concentration in a well-formulated product, not some magical version from BHT Berlin or an online market converting baht to euro, baht to gbp, baht to pounds, or baht to usd. In cosmetics, BHT is simply a practical little oxidation blocker doing boring-but-important work.

There’s been some controversy because high-dose oral studies have looked at safety, but that’s a very different story from the tiny amounts used on skin. So if you’re asking what does a BHT do in a cream, the answer is: it helps keep the formula from aging badly. Not glamorous, but extremely useful. And no, it has nothing to do with how to use TikTok or BH Telecom, though the internet does love to send people on wild ingredient scavenger hunts.

It's the acronym for Butylated Hydroxy Toluene. It's a common synthetic antioxidant that's used as a preservative.

There is some controversy around BHT. It's not a new ingredient, it has been used both as afood and cosmetics additive since the 1970s. Plenty of studies tried to examine if it's a carcinogen or not. This Truth in Aging article details the situation and also writes that all these studies examine BHT when taken orally.

As for cosmetics, the CIR (Cosmetic Ingredient Review) concluded that the amount of BHT used in cosmetic products is low (usually around 0.01-0.1%),  it does not penetrate skin far enough to be absorbed into the bloodstream and it is safe to use in cosmetics.