Why we love it: Experts, and the whole Cosmo team, are obsessed with growth factors. How do they work? Well, they stimulate fibroblasts, which are the cells responsible for producing more collagen. We naturally start losing collagen at about 25, and it’s the key to skin that’s plump and firm. BioEffect has been at the forefront of the growth factor conversation for years, and this day serum makes implementing this powerful ingredient into your routine so easy. Just once a day, massage this lightweight serum into your skin, and over time, it’ll help fight wrinkles, speed up wound healing, and even improve the skin barrier.

One Cosmo editor’s review: “I can’t even express how much I love this serum. I’m 26, so i want to get on my preventative serum game, but retinol and heavy formulas simply irritate my skin. however, this is hydrating and formulated with high-tech growth factors to promote collagen production, so i really get the best of both worlds here.”—JASMINE HYMAN, ASSISTANT BEAUTY EDITOR