This Easy Trick Will Help Your Foundation Look Seriously Dewy

To elevate your base makeup, add a few drops of serum or face oil to the formula. The advice is nothing new—makeup artists have endorsed this tip for years—however, the type of product you drop into the mix matters: Liquid highlighter, for example, will offer more of an allover glow, while a rich face oil will add much-needed moisture and deter flaky makeup.

First, let's discuss what this sciencey-sounding active is, exactly: Polyglutamic acid (PGA) is a humectant derived from fermented soybeans, meaning it draws in water to the surface of the skin (just like hyaluronic acid, the buzzy humectant we all know and love). In fact, "Polyglutamic acid is a powerful humectant that can hold four times more water than hyaluronic acid," says board-certified dermatologist Hadley King, M.D. Hyaluronic acid holds up to 1,000 times its weight in water, for reference, so with a little mental math, that means PGA holds up to 4,000 (!) times its weight in water. Talk about a fabulous hydrator. 

"It's a surface hydrator, so it smooths and plumps your skin and works so well with foundation," notes fashion and beauty influencer Maxie Elise in a recent TikTok video. By "surface hydrator" she means humectant—since these ingredients draw water into the top layer of the skin, they can instantly plump the skin with hydration. Think about how a dry sponge rises under water, board-certified dermatologist Ava Shamban, M.D., once told me. "Run it under water, and it is instantly plump, dense, and smooth. Even the color is brighter." And as Elise notes, PGA blends quite seamlessly with makeup formulas; in fact, it plays nice with a bunch of ingredients, even notoriously finicky vitamin C. 

Of course, a seamless makeup application always starts with a hydrated base, so make sure to include humectants (like PGA) in your proper skin care routine as well.