Additionally, some companies actually create synthetic, human-identical collagen using a process called ultra pure fermentation. “It’s a patented technology that uses renewable plant-based inputs,” explains clean cosmetic chemist Krupa Koestline. “There are companies using vegan marine-like collagen as well, but in my opinion, a human-identical collagen works best topically.” And as the technology becomes more accessible, she notes we’ll start to see it in a ton of beauty products—in fact, several brands have incorporated it already.