You buy sunscreen to protect your skin. But what if the sunscreen itself is the problem?
It sounds contradictory, but for a growing group of dermatologists, toxicologists and concerned consumers, the question is no longer whether certain sunscreens are harmful - but to what extent. The most frequently named culprit: oxybenzone.
In this article we explain what oxybenzone is, why it is in so many products, which other harmful ingredients turn up in sunscreen, and what you can do if you are looking for a safer alternative.
What is oxybenzone and why is it in sunscreen?
Oxybenzone (also written as benzophenone-3) is a chemical UV filter that is widely used in sun care products. It absorbs both UVA and UVB rays effectively, is cheap to produce and blends well into light, transparent formulas. That makes it popular with manufacturers who want a cosmetically appealing end product - no white cast, easy to spread.
Sounds good. Until you look at what happens next.
Oxybenzone is absorbed into the body
Several studies - including a large American study published in the journal JAMA (2019) - showed that oxybenzone is detectable in the blood after a single application. After four days of daily application, concentrations were far above the threshold the FDA uses for substances that require further safety testing.
Oxybenzone has also been found in breast milk, urine and amniotic fluid. That means the substance doesn't just pass through your skin, but spreads throughout the body.
Oxybenzone as a hormone disruptor
The main concern around oxybenzone is its potential hormone-disrupting effect. In laboratory research, oxybenzone behaves like a weak oestrogen: it binds to hormone receptors and can thereby influence hormonal signalling. At higher exposure, effects on thyroid function and the reproductive system have been shown in animal models.
The European Union has already tightened the maximum permitted concentration of oxybenzone in cosmetics several times. Several countries and regions - including Hawaii and the US Virgin Islands - have banned products containing oxybenzone altogether, specifically because of damage to coral reefs and as a precaution for public health.
Is there proof that oxybenzone causes direct harm in humans? Not conclusively, not yet. But the precautionary question is a fair one: why would you apply a substance to large areas of your body, several times a day, that demonstrably enters your bloodstream and behaves like a hormone?
Other harmful ingredients in sunscreen
Oxybenzone is not the only ingredient that raises critical questions. A number of other common ingredients in conventional sunscreens deserve attention.
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Octinoxate (octyl methoxycinnamate)
Another widely used chemical UV filter with similar concerns to oxybenzone. Also shown to be a hormone disruptor in animal studies, also measurable in blood and breast milk, also banned in Hawaii. Often combined with oxybenzone in a single product.
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Homosalate
Long considered safe, but recently reassessed by the European safety authority SCCS. The conclusion: the current maximum concentrations are too high to be safe. The EU has tightened the limits. Homosalate has a potential hormone-disrupting effect and accumulates in the body.
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Octocrylene
A stable UV filter that, in older products, breaks down into benzophenone - a substance linked to carcinogenicity. In 2021 the SCCS published a negative opinion on octocrylene at high concentrations. Using sunscreen without harmful ingredients consciously also means: watching out for octocrylene in products that have been sitting in your bathroom cabinet for a while.
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Avobenzone
More stable in itself than oxybenzone, but in formulas it is often combined with octocrylene (for stabilisation), which shifts the concern to that ingredient. Avobenzone itself is less problematic, but the combinations it requires sometimes are.
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Synthetic fragrances and preservatives
Not specifically UV filters, but common in sunscreens: synthetic perfumes (allergens), BHT, and methylisothiazolinone - a preservative linked to contact allergy and neurotoxicity at high doses.
What makes a sunscreen truly safe?
The question "is sunscreen harmful?" has no simple yes or no answer. But the question of which sunscreen is safer does.
The answer lies in the choice of UV filter. There are two types recognised by the FDA as safe and effective: zinc oxide and titanium dioxide. These are mineral filters. They don't work by being absorbed into the skin, but by physically reflecting UV rays at the skin's surface.
They don't penetrate. They don't disrupt hormones. They are not measurable in the blood after use.
Anyone who chooses a sunscreen without oxybenzone and the other chemical filters will, in practice, almost always end up with a mineral formula. And those formulas have improved greatly in recent years: lighter textures, better spreadability, and hardly any of the white cast that used to be typical.
WONDR Mineral Sunscreen SPF 30: safe protection without compromise
WONDR Mineral Sunscreen SPF 30 was developed from exactly this reasoning. No oxybenzone, no octinoxate, no homosalate or octocrylene. Only non-nano zinc oxide as the UV filter - effective, transparent and hormone-neutral.
The formula is built with skin-friendly ingredients: sunflower oil and shea butter nourish the skin barrier, aloe vera soothes, and double antioxidant protection from vitamin E (tocopherol) and vitamin C (ascorbyl palmitate) work together to tackle the free radicals created by UV radiation. Fast-absorbing, not sticky
Suitable for daily use, including under make-up. Water-resistant enough for the outdoors and sport!
View the WONDR Mineral Sunscreen SPF 30 →