Octinoxate Is in Many of Your Favorite Sunscreens—We Asked Derms to Explain Why

Drink water, don’t sleep in your makeup, and wear sunscreen. In beauty, there are no rules, but if there were, those would be the three commandments. And while most of us can get behind the first two, sunscreen has come into question in recent years, specifically the safety of the ingredients used in the formulas. Just as many of us were starting to make sunscreen application a daily habit, news of traditional chemical filters used in sunscreen, such as octinoxate, having less than positive effects on the environment and potentially even our bodies has come into the light.

But before you swear off octinoxate completely, hear what skin experts have to say about this ingredient that’s commonly found in sunblock. We interviewed board-certified dermatologists Rachel Nazarian, MD, FAAD, of Schweiger Dermatology Group and Hadley King, MD, and chemists Victoria Fu and Gloria Lu of Chemist Confessions.

Find out what they think you should know about octinoxate.

What Is Octinoxate?

Octinoxate is an organic compound that is insoluble in water and can be found in all textures (lotions, creams, balms, and liquids) of chemical sunscreen due to its protective ability against certain wavelengths of ultraviolet (UV) light. Nazarian says that it primarily blocks the UVB range, though it also offers minimal protection against UVA rays. Unlike mineral sunscreens, which reflect the UV rays, chemical sunscreens work to protect the skin from damage by absorbing the UV light and turning it into heat instead.

Benefits of Octinoxate for Skin

Octinoxate is a popular ingredient in traditional chemical sunscreens for its aesthetics, texture, and ability to protect the skin. See below for a further explanation of its benefits.

• Protects skin from sunburns: As a UVB filter, octinoxate's primary function is to stop the sun from burning the top layers of the skin.
• Decreases potential for skin cancer: Nazarian says by preventing sunburns, it also minimizes the risk of skin cancers, including basal cell carcinoma, squamous cell carcinoma, and melanoma.
• Prevents damage: Studies show that UV radiation can generate free radicals and cause DNA damage and skin aging. Although octinoxate primarily protects against UVB rays, it also offers some protection against UVA rays, which penetrate deeper into the skin and damage the skin cells.
• Minimizes signs of photoaging: Nazarian adds that octinoxate can help reduce premature skin aging. UV radiation from sun exposure can cause collagen degradation and lead to wrinkles, dark spots, and loss of skin elasticity.
• Applies smoothly: Chemical sunscreens, in general, have a lighter texture than mineral sunscreens. Formulas containing octinoxate apply smoothly and evenly and are easy to layer under makeup.
• Leaves no white cast: Sunscreens containing octinoxate have less chance of leaving a white cast on the skin than mineral sunscreens.

Side Effects of Octinoxate

In general, octinoxate is recommended for most people. However, those with melasma or sensitive skin might have better luck with a mineral formula: "Melasma is a condition that requires protection against the entire UVA and UVB spectrum and even visible light," Nazarian says. "Iron-based sunscreens have done a superior job in people with melasma, so I would not recommend sunscreens with only octinoxate for this population. I would also recommend those with sensitive skin to consider a physical or mineral sunscreen rather than a chemical blocker such as octinoxate to minimize risk of irritation."

Additionally, although octinoxate has a solid safety record and allergic reactions to it are uncommon, there are concerns that it could be an endocrine disruptor, notes King. As Nazarian notes, octinoxate has been shown to have potential for hormonal disruption and neurologic toxicity. "However, the studies were done in settings that had oral ingestion and other extremely high doses, which are not 'relevant to human exposure.'" In other words, Nazarian says it’s safe when used normally and applied topically as a sunscreen. And, research shows that, when applied topically, only .002 percent of the topical amount is absorbed in the body—"a minuscule amount," Nazarian adds. Lu agrees: "We know that there is ongoing research being done to further look into these ingredients and see if any of these truly are endocrine disruptors, but for now, there’s no concrete validity."

Is Octinoxate Reef-Safe?

Following Hawaii's ban on the sale of sunscreens containing octinoxate, some are worried about the ingredient's impact on the coral reef. Studies have shown that octinoxate and oxybenzone can have harmful effects on coral, "but there’s still a lot of questions on how this translates to our oceans," Fu says. "The ocean habitat is much more complex, and sunscreens may only play a small part amongst poor wastewater management and global warming," she adds. While we wait for more research to come out, Fu recommends using mineral sunscreen when snorkeling around the reefs. In these instances, look for formulas designated as "reef safe," or when in doubt, go with a zinc oxide-based formula.

How to Use It

According to the Skin Cancer Foundation, sunscreen with an SPF of 30 should be applied to dry skin 30 minutes before sun exposure and should be reapplied every two hours and after swimming or sweating. Nazarian stresses the importance of application order when it comes to sunscreen, stressing that you apply it to clean, dry skin before applying your moisturizer or makeup. When using sunscreen on your entire body, use one ounce of the formula (that's about the size of a shot glass) to make sure your skin is sufficiently covered.