Key Takeaways:“Sunscreen doping” has surged in recent years as skincare brands race to develop formulations that meet the rising consumer demand for cast-free, high SPF mineral sunscreen.SPF boosters, like butyloctyl salicylate and tridecyl salicylate, aren’t FDA approved as UV filters, but experts say these ingredients can increase SPF by 10-30 points. Unless the FDA changes course and requires these ingredients to be labeled as what they functionally are, companies have little incentive to seek FDA approval for SPF boosters.What is the best way to make a mineral sunscreen that doesn’t suck? Ask a formulator off the record and you’ll often hear a version of the same answer: You add a sprinkle of ingredients that behave a lot like chemical sunscreens.Inside labs, the practice has a name: “sunscreen doping,” a term coined by chemical-biomedical engineer Sophie Bai, founder and CEO of Pavise. It’s a tactic that’s surged in recent years as skincare brands chase cast-free, high-number “100% mineral” claims. By functionally “boosting” mineral SPF with chemical sunscreen ingredients, brands get a formula that has the lightweight texture of a chemical sunscreen without having to disclose it on the back of the box.“SPF boosters are a pretty broad range of ingredients that increase the SPF of the sunscreen … They’re not technically sunscreen actives, so they’re not in the Drug Facts panel,” chemistry PhD and science communicator Dr. Michelle Wong told BeautyMatter. “Some are just solvents that help pigments spread more evenly, some stabilize UV filters, and some essentially act as chemical sunscreens.