why octinoxate in sunscreen is not dangerous

Another day, another UV filter that gets a bad rep.

Seriously, if you were to believe the rumours going around about UV filters, you’d just skip sunscreen and call it a day. And then wonder why all of a sudden you have wrinkles creeping up on your face left, right and centre…

You need sunscreen. And you need it to be safe. That means going to the bottom of these rumours and figure out which UV filters are good and which are bad.

First one on the witness stand: Octinoxate. It’s accused of causing cancer and hormonal imbalances. Is this true? Let’s examine the evidence:

What Is Octinoxate?

Octinoxate is the easy-to-remember name for Octyl methoxycinnamate. For the nerds among you, it’s an ester formed from 2-Ethylhexanol and Methoxycinnamic Acid.

How Does Octinoxate Benefit Skin?

Octinoxate is an UVB filter. It protects skin only from UVB rays and the sunburns and DNA damage they cause.

According to smartskincare.com, “when exposed to sunlight octyl methoxycinnamate is converted into a less UV absorbent form (from E-octyl-p-methoxycinnamate into a Z-octyl-p-methoxycinnamate)”.

In plain English, this means that when you expose it to sunlight (and it needs to be exposed to sunlight or what’s the point of wearing sunscreen?), it loses some of its effectiveness.

Thankfully, there’s a workaround. Add other UV filters that can prevent this conversion, such as Tinosorb M.

Related: Is Tinosorb The Perfect UV Filter?

Is your sunscreen up to the job? Download your FREE “Sunscreen Audit” cheatsheet below and make sure your sunscreen is both safe AND effective:

Does Octinoxate Cause Cancer?

Short answer: no. There’s no evidence that Octinoxate causes cancer (or hormonal disruption and any other health problems, for that matter).

The long version: Octinoxate still isn’t dangerous for you. The rumours originated from a few studies that Octinoxate is toxic for rats – when they eat a truckload of it or scientists apply it to their uterus and liver cells.

An example? In 2004, scientists at the University of Zurich fed rats Octinoxate and found it to disrupt their hormonal balance. But rats aren’t humans. Just because something hurts them, it doesn’t mean it will hurt us, too.

Plus, we don’t eat Octinoxate. You slather it on your skin. That’s a huge difference. To say that sunscreens with Octinoxate cause cancer in humans because rats that were forced to eat too much of it got cancer is bad science.

Can Octinoxate Be absorbed By Your Body?

The other rumour that’s scaring people off: Octinoxate is absorbed by your body. That’s proof it will kill you. 🙄

In 2005, researchers in Australia found traces of Octinoxate in the stratum corneum and epidermis 24 hours after it was applied on the skin. Their conclusion?

The amount of Octinoxate in the epidermis was “at least 5-fold lower, based on levels detected in viable epidermal cells, than those appearing to cause toxicity in cultured human keratinocytes. It is concluded that the human viable epidermal levels of sunscreens are too low to cause any significant toxicity”.

Translation: the amount of Octinoxate in the epidermis is too low to cause any health problems.

If you’re pregnant/breastfeeding or using sunscreen on a young child, I’d avoid Octinoxate and use a mineral sunscreen instead. They’re gentler. But there’s no reason why all other adults can’t use it.

Related: What Skincare Ingredients Should You Avoid During Pregnancy?


The Real Danger Of Octinoxate

Octinoxate doesn’t play well with Abovenzone, the most used UVA filter in the world.

When exposed to sunlight, Octinoxate degrades both itself and Avobenzone, which isn’t very stable to begin with. It’d be too long and boring to explain how this happens. If you’re curious, you can check out this detailed post by John Su’s at Future Derm.

All you need to know is this degradation makes your sunscreen ineffective. To slow it down and make sure you’re protected for at least a couple of hours, formulators add stabilisers like Octocrylene.

Still, if your sunscreen has both Octinoxate and Avobenzone, it’s not a bad idea to reapply it very frequently.

Related: Why Avobenzone Is The Most Used UV Filter In The World

What Are The Best Sunscreens With Octinoxate?

The Bottom Line

Octinoxate isn’t toxic and won’t give you cancer. Just make sure you avoid pairing it with avobenzone.