US & Europe · Independent Updated August 2026
The Banned in Europe Registry
Explainers

Europe Capped Your Brightening Serum at 1%. The Twist? Its Own Scientists Wanted It Lower.

Kojic acid didn't get banned in Europe. It got a number. And the story of how the EU landed on that number says more about data gaps than about danger.

By 8 min read Explainers

If you’ve bought a brightening serum in the last few years, you’ve probably rubbed kojic acid into your face without thinking about it. It’s the quiet workhorse of the “even tone” aisle: a compound first pulled from the same mold that ferments sake and soy sauce, now sitting in thousands of dark-spot correctors, post-acne fade creams, and melasma treatments. And in 2024, Europe decided you were allowed to keep using it. Just less of it.

That’s the part worth slowing down on. Because if you’ve seen kojic acid pop up on a “banned in Europe” list, that list is wrong. What actually happened is more interesting, and honestly, a little more uncomfortable for the tidy version of the story where Brussels swoops in and protects everyone while America shrugs.

What the regulation actually says

In April 2024, the European Commission published Regulation (EU) 2024/996. Among a batch of other ingredient updates, it moved kojic acid (CAS 501-30-4) onto Annex III, the list of substances cosmetics can use only under specific conditions. The condition: a maximum of 1% concentration, and only in face and hand products.

Then it set two deadlines, the way the EU usually does. From 1 February 2025, no product that breaks the new rule could be placed on the market. From 1 November 2025, non-compliant products already in the supply chain could no longer be sold at all. So as of late 2025, a compliant kojic acid product in the EU tops out at 1%, and you won’t find it in a body lotion or a full-body brightening wash.

That’s a restriction. It is not a ban. The distinction matters, and not just as pedantry: a ban says “this ingredient is unsafe, full stop,” and a concentration cap says “this ingredient is fine within limits we’ve drawn.” Europe drew a limit. Kojic acid stayed legal.

Why the thyroid, of all things

The concern that put kojic acid on the review list has nothing to do with your skin. It’s your thyroid.

Kojic acid can interfere with how the thyroid takes up and processes iodine, the raw material your body uses to make thyroid hormone. In animal studies, enough of it, absorbed over enough time, nudged thyroid function. That’s the mechanism that flagged it as a possible endocrine disruptor, a substance that meddles with the hormone system rather than causing acute harm. The worry was never one serum on one cheek. It was cumulative, whole-body absorption, day after day, especially through skin that’s already compromised. Kojic acid sometimes shows up in peeling products, and a weakened skin barrier absorbs more of whatever you put on it.

So the EU’s Scientific Committee on Consumer Safety, the SCCS, took another look. They’d assessed kojic acid back in 2012 and called 1% safe. This time, with the endocrine question sharpened, they reached a different conclusion.

The twist the headlines skipped

Here’s where the “Europe protects you” narrative gets complicated, and where the honest version pays off.

The SCCS’s final opinion, adopted in March 2022, did not endorse the 1% figure. It said the opposite. It concluded that 1% was no longer considered safe for the intended use, and recommended a maximum of 0.7% for kojic acid as a whitening agent. And when the committee tried to account for the realistic scenario, someone using a kojic acid face cream and a kojic acid hand cream, twice a day, the number it floated was startling: to keep total exposure inside the safe margin, the concentration shouldn’t exceed roughly 0.04%.

Read that again. The committee’s own aggregate-exposure math pointed to a fraction of a percent. The regulation landed on 1%.

How does that gap happen? Mostly through a data hole. The SCCS said plainly that industry hadn’t supplied enough information on how many different kojic acid products a typical person uses at once, so the committee couldn’t confidently set a safe per-product concentration for the real world. The Commission’s answer was to cap each product at 1% and wall the ingredient off to face and hand use only, betting that limiting where you apply it, rather than how concentrated it is, keeps total absorption low enough. That’s a defensible regulatory call. But it is not the same thing as following the science to its strictest reading. It’s a compromise, shaped by a missing dataset.

If you want to feel good about European regulation, the honest reason isn’t that it always lands on the most cautious number. It’s that the process is public. You can read the SCCS opinion, see the 0.7% and the 0.04% figures, watch the Commission choose 1%, and judge the tradeoff yourself. The disagreement is on the record. That transparency is the actual product.

What America does instead

In the United States, there is no federal concentration limit on kojic acid in cosmetics. There’s barely a federal anything.

The FDA does not approve cosmetic ingredients before they go on sale, with the narrow exception of color additives. Kojic acid isn’t a color additive, so it enters the market without a pre-market safety sign-off. The closest thing the US has to Europe’s SCCS is the Cosmetic Ingredient Review, an industry-funded expert panel whose findings carry weight but not the force of law. The CIR looked at kojic acid and judged it safe at up to 2% in leave-on products. Nobody has to follow that number, but in practice it’s the informal ceiling a lot of American formulators use, which is why plenty of US brightening products sit at 1% to 2%, above what an EU product can now contain.

There’s a second American wrinkle that’s easy to miss. In US regulatory logic, “lightening the skin” is a drug claim, not a cosmetic one. A product that promises to lighten your skin is, on paper, an unapproved drug. In theory that gives the FDA a lever. In practice, enforcement is sporadic, the shelves stay full, and the ingredient keeps flowing. So the US ends up in a familiar spot: a stricter rule on paper, applied loosely, versus Europe’s looser-sounding rule that’s actually written into binding law with deadlines and market withdrawals attached.

This is the pattern that shows up again and again once you start looking. It’s the same shape as the story behind the EU’s 2026 cosmetics restrictions and the one behind how a glaucoma drug ended up in lash serums: the interesting divergence usually isn’t “banned versus allowed.” It’s how each system handles uncertainty, and who bears the risk while the uncertainty gets sorted out.

Should you throw out your serum?

Probably not, and the calibrated answer is worth stating plainly rather than hedging into mush.

Kojic acid at the concentrations in a normal, reputable brightening product is not an ingredient anyone credible is calling dangerous. The thyroid signal came from cumulative, whole-body exposure scenarios, not from dabbing a 1% serum on a few dark spots at night. The EU didn’t pull it from shelves; it capped it and narrowed where it can go. That’s a measured response to a real but modest question mark, which is roughly the response the evidence supports.

If you want to be conservative, the sensible moves are boring ones. Keep kojic acid to your face and hands, which is exactly where the EU now confines it. Don’t layer three different kojic acid products at once, because the concern is total dose, not any single tube. Be a little more careful applying it over freshly exfoliated or broken skin. And if you’re pregnant or have a known thyroid condition, that’s a reasonable thing to raise with a dermatologist, not because there’s proof of harm, but because the specific mechanism in question is a thyroid one.

If you’d rather sidestep the whole debate, the brightening aisle is crowded with alternatives that work through similar pathways and didn’t draw the same flag. Alpha-arbutin and niacinamide-based formulas are the usual off-ramps, and retinol, which the EU also just put new limits on, does tone-evening work of its own. Kojic acid’s more potent cousin, hydroquinone, is a genuinely different regulatory story, restricted far more tightly and worth its own read.

The takeaway

Kojic acid is a good test case for how to read a “banned in Europe” claim. Nine times out of ten, “banned” turns out to be “restricted,” and the restriction turns out to have a number, a scope, and a set of dates attached. Here the number is 1%, the scope is face and hand products, and the dates are already behind us.

The part the viral version leaves out is that Europe’s own scientists wanted a tighter number, and the reason they didn’t get one is that the industry never handed over the data to justify it. That’s not a scandal. It’s just how regulation works when the science outruns the paperwork. It’s also a decent reminder that “the EU restricts this” and “the EU has this figured out” are two different sentences, and BIE exists to keep them apart. If a calmer, better-informed version of your shelf is the goal, that difference is the whole game, and it’s the same thread running through why so much of this feels different in Europe.

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