As you are well aware by now, daily SPF is a non-negotiable for healthy skin. I got the memo years ago when I first started using retinol and I’ve been loyal ever since. So imagine my surprise at a recent consult with Bell Yoo, MSN, FNP-C at Facile Dermatology + Boutique when she suggested I let go of my trusty preferred sunscreen as part of my treatment plan for hyperpigmentation (sorry Shiseido, I loved you so!). Turns out, I was unknowingly using a chemical formula, which may in fact make hyperpigmentation and melasma worse. So why does this happen? Bell gave us all the details.
First, let’s break down the types of sunscreen there are on the market. They can be separated into two camps: physical (aka mineral) and chemical. “The active ingredients and its mechanism of action is what differentiates the two types,” says Bell. There are pros and cons to both types — Bell notes that chemical formulas don’t leave a white cast and are generally easier to blend, whereas physical formulas can be harder to wear. However, physical formulas won’t clog pores and are effective against UVA and UVB rays immediately upon application, while chemical formulas need 20-30 minutes to become effective and can irritate sensitive skin.
What really sets them apart from one another is the mechanism of action — basically how they protect you from UV rays. “Physical sunscreens work by sitting on top of the skin’s surface and acting like a physical shield or barrier — they reflect UV rays like a mirror,” she says. “Chemical sunscreens work by absorbing UV rays into the skin and converting the UV rays into heat, which is then released by the skin.” This is where it starts to affect hyperpigmentation. “Melasma is often exacerbated not only by sun exposure, but by heat as well,” Bell explains. “Heat can cause inflammation and stimulate melanocyte pigment in the skin.” So for people prone to these conditions (like me), chemical sunscreens are probably not the best choice.
So, how can you know whether your next bottle of SPF is physical or chemical? The key is to check out the ingredients. “Physical sunscreens contain mineral active ingredients such as titanium dioxide and zinc oxide, while chemical sunscreens contain chemical active ingredients such as oxybenzone, avobenzone, octinoxate, octocrylene, octisalate, homosalate, or combinations thereof,” says Bell. Keep your eyes peeled for those and you’ll be golden.
As for Bell’s favorite sunscreens? She says you can’t go wrong with Elta MD. For a 100% physical option, check out Elta MD UV Elements. “I recommend this to patients with melasma or pigmentation,” she says. “It has a universal tint which helps to mask any white cast, and it contains hyaluronic acid to help hydrate the skin.” If you can handle a mixed formula, try Elta MD UV Clear. “This is my all time favorite sunscreen that is ideal for acne-prone skin,” she says. “It contains mostly transparent 9% zinc oxide, 7.5% octinoxate, and skin beneficial ingredients like niacinamide and hyaluronic acid.” Remember: no matter which sunscreen you ultimately choose, the most important thing is to apply liberally and reapply throughout the day. As for me? I switched to a physical formula immediately — now that I know what I know, there’s no going back.