As a skin-care writer, I rarely hear about vitamin F — which technically isn't a vitamin at all, it turns out. But just because it's lesser-known doesn't mean it's not a powerhouse ingredient, and if there's one skin-care brand that can put it on the map, Drunk Elephant is it. The beloved line, recently sold to Shiseido, is launching another high-performing skin-care product just in time for winter (aka parched-skin season). And just as you'd expect from the brand, it's got a cheeky name: F-Balm, which refers to vitamin F in the formula.

As I mentioned, vitamin F is not really a vitamin, like vitamin C or B. In the skin-care world, it actually refers to two essential fatty acids, linolenic and lenoleic acid, with the "F" literally standing for fat or fatty. Both of these acids are essential to the body for various reasons, "but the body cannot create them and relies on us to provide them via food or topically," explains cosmetic chemist Ni’Kita Wilson, who is not affiliated with Drunk Elephant. "In skin care, vitamin F is used for a nourishing and repairing effect to improve the condition of the skin. You'll likely find vitamin F in products that address dry to severely dry skin and scalp."

Board-certified dermatologist Dhaval Bhanusali, also unaffiliated with the brand, agrees with Wilson, explaining that both acids "help maintain the integrity of your superficial skin layers" by "maintaining healthy, plump skin." And that is exactly what F-Balm promises, courtesy of tiny beads of vitamin F that are said to explode during application to quench parched skin.

The idea for the F-Balm — full name: F-Balm Electrolyte Waterfacial — came about as a sort of sister, albeit oppositely intended, mask to the brand's fan-favorite T.L.C. Sukari Babyfacial. "We definitely had room in our line for a mask that focused on hydration, moisture, and repair, and customers were beginning to ask for one," explains Drunk Elephant founder Tiffany Masterson, who says it took her and team 12 different versions to nail the final formula. "I wanted to develop a hardworking, intensive repair treatment for when skin is extra-parched, stressed, or just needs a little extra love. F-Balm is a much more concentrated mix of reparative ingredients that is specifically designed to layer on as a last step."