After decades of shopping and writing about skincare products, I've developed a skill for distinguishing marketing claims from genuinely breakthrough science. Elm Biosciences – and more specifically their A3O™ Complex – falls squarely in the latter camp. 

A3O™ is  a patent-pending ingredient developed by board-certified dermatologist Dr. Dhaval Bhanusali alongside an advisory board of more than 350 dermatologists, scientists, and researchers, and it’s clinically proven to outperform vitamin C on visible skin age and barrier function. It also happens to be the brand behind Martha Stewart’s seemingly age-defying skin (she actually co-founded the brand). I’m a few months into testing it, and I’m floored by my results. Here’s what I've learned…