Feel Like Your SPF Only Pills Sometimes? That’s Because It’s Interacting With *These* Ingredients in Your Other Products

Right now, my absolute favorite SPF is Kosas Dream Beam ($40). It’s a mineral SPF that goes on smoothly, the white cast blends away, and it never pills. At least that was the case until I tried to layer it over the gorgeous Odacité Brightening Serum ($78). It has a gel-like texture that feels amazing and dries down fast, but it does not play well with Dream Beam—the two together make a pilly mess. I thought this was something that only happened when you put makeup over certain SPFs, but clearly, our pre-SPF skin-care products can create the same issue. So I asked a chemist: “Why is my sunscreen pilling?”

“Pilling tends to happen when film formers in a product clump up when exposed to an incompatible ingredient, usually a solvent—for example, water, oil, or silicone,” explains Michelle Wong, MD, a cosmetic chemist based in Sydney, Australia. “It tends to happen when you rub the product.”

None of these ingredients are “bad” ingredients. But when you’re mixing different skin-care items (especially across multiple brands) you’re bound to run into some bad matches. That’s why you may notice that your go-to SPF only pills sometimes. And not only does this make a mess, it means the sunscreen isn’t really staying on your face. “The pilling is sunscreen coming off your skin,” says Dr. Wong.

To keep your SPF on your face and not in little balls on your bathroom counter, it’s time to get a little savvy.

How to prevent sunscreen pilling

1. Limit skin care under your sunscreen

Your best bet is to keep the skin care under your SPF minimal. “It’s hard to say what ingredients to avoid, I would just try to minimize using anything underneath sunscreen,” says Dr. Wong. But if your seven-step routine is quaking at the thought, keep reading.

2. Let your routine fully dry before putting on SPF

This is a step you should follow regardless of whether or not you’re concerned about pilling. “If you put a mineral sunscreen on wet skin, it doesn’t go on,” says, Shirley Chi, MD, a board-certified dermatologist in Southern California. And while chemical sunscreen may blend into wet skin, it’s not going to work as well, because it interacts with the top layer of your epidermis, to absorb ultraviolet rays so they don’t go cause damage. “If you’re applying it to wet skin, then that’s going to affect the absorption of the chemical sunscreen,” says Dr. Chi.

3. Take a look at the ingredients

Unless you’re a literal chemist and know how to interpret ingredients very well, this step can be pretty hit-or-miss, but it’s a great place to start. For example, when I asked Dr. Wong why my two products didn’t like each other, she said “Not really sure, I’d have to play with them and test how they interact with other serums and sunscreens—I would guess perhaps it’s the cellulose acetate butyrate in the Odacite.”

To do your own analysis for funsies, you can pop the ingredient lists for your products into Paula’s Choice Beautypedia. It’s a skin-care search engine where you can filter the ingredients by purpose and see if any opposing ingredients stick out to you.

4. Give yourself time to start over if necessary

If all else fails and your new skin-care-SPF combo don’t play well with each other, you’re going to want to run it back and try again with different pairings. “Just make sure you have some extra time to wipe everything off and start over if you’re about to test a new combo,” says Dr. Wong.