Kelly Dobos, a cosmetic chemist based in Cincinnati, did some digging and points to Crithmum maritimum extract and Crithmum maritimum callus culture filtrate—both derived from coastal plants—as two marine ingredients of particular interest in the formula. “There are studies that show potential benefits for collagen and skin renewal, but those experiments were conducted on cells or reconstructed skin rather than people,” says Dobos. To be fair, La Mer does have some numbers to back up its claims. In a study of 31 people, the brand found that the finished Rejuvenating Night Cream improved eight signs of aging, including fine lines, plumpness, firmness, smoothness, texture, and wrinkles. However, the testing was small and done on the cream as a whole, so there’s no way to tease out how much of those results came from MRA-3 versus everything else packed into the formula.
Then there’s La Mer’s other big signature: Miracle Broth, the proprietary blend found throughout the brand’s lineup. It starts with sustainably harvested Giant Sea Kelp, which is fermented with other ingredients for about four months to create a broth the brand says helps soothe irritation, support the skin barrier, and encourage a healthier, more resilient complexion. Here’s the cool part: A few drops from the previous batch are added to every new one, creating a sort of continuous lineage of Miracle Broth.
Not everything in the jar is as mysterious as MRA-3 and Miracle Broth, though. In fact, some of the more familiar ingredients may actually be responsible for a lot of the instant gratification I noticed. Shea butter, glycerin, dimethicone, jojoba oil, mango butter, and sodium hyaluronate form a seriously moisturizing lineup. “Humectants such as glycerin attract and retain water, while the emollients and occlusives smooth skin and help curb moisture loss,” says Dobos. That could also explain why my fine lines looked noticeably blurred right away. But the immediate effect “is likely due to the hydrating elements of the formula rather than longer-term changes in the skin,” says Dr. Son.