Some sunscreens are more easily absorbed into the body compared to others. Octocrylene used to be a very popular sunscreen filter for two main reasons – note the emphasis on used to be. The skin feel of such sunscreens used to be amazing – sunscreens with octocrylene were among the first ones to charm Indian users with all our humidity issues. The second reason why experts loved this ingredient was its ability to stabilise the other unstable ingredients in a sunscreen formula.

But now, octocrylene is in the news for its ability to cause potential endocrine disruption. In fact, it was implicated in PCOS among women with high BMI, other than studies that demonstrated just absorption. And the absorption seems to be a function of reapplication.

A recent study examining octocrylene absorption found that this lipophilic UV filter isn’t just sitting on your skin—it penetrates and remains in the body for days. Researchers measured plasma and urine levels in volunteers who applied sunscreen containing octocrylene, revealing peak concentrations in 10–16 hours. What’s more, its metabolite CDAA persisted, with a half-life of 1.5 to 2 days, indicating a skin depot effect. This means octocrylene gradually releases into the body over time, and has the potential to accumulate with frequent use.

This may have to do with the oil loving character of octocrylene – the same feature that gives a good skin feel, unfortunately seems to be contributing to the absorption. Still, octocrylene does not fare as the more notorious oxybenzone, which we will discuss next.