Maybe you’ve heard of “natural DIY sunscreens” or that plant oils provide sun protection. I see it constantly written about in the wellness community as a great “chemical-free sunscreen option.” Particularly coconut oil.
Coconut oil is by far the most popular when the DIY community thinks of “natural” sunscreen. This belief may have started after just a single 2009 study suggested that coconut oil can act as sun protection with SPF 7. However, this study was conducted in a petri dish, not on human skin. This leaves a lot of room for inaccuracy.
In 2011, the FDA also put out new sunscreen guidelines that require researchers to apply sunscreen to 10 human participants and measure how long it takes before sunburn occurs. These guidelines help ensure that the products protect against UVA and UVB rays and sunburn. If you were to DIY your own sunscreen, it would be very difficult to prove how protective your homemade recipe is. It’s unlikely to meet the requirements for today’s guidelines.
It’s imperative that a sunscreen provides either UV-absorbing or UV-blocking protection to be effective. I couldn’t find one scientific study proving coconut oil, or any other natural oil for that matter, provided any adequate UV-absorbing or UV-blocking protection. But as far as zinc oxide (the main ingredient for sun protection in these DIY recipes), mixing active cosmetics isn’t as simple as adding the recommended amount.
It’s because sun protection is one of the most difficult products to formulate. It requires significant, expensive testing to be deemed safe and effective. There’s a whole lot of chemistry, years of testing, and proper ratios of active and inactive ingredients that go into creating a well-formulated sunscreen.