At a recent women’s health medical conference, I discovered something that stirred my curiosity. Between sessions, at dinners, and in hallway conversations, nearly every physician I spoke with was using estradiol on their face. Gynecologists, dermatologists, internists, menopause specialists: the "estrogen face cream" trend wasn't just on social media. It was happening among the people who write the prescriptions. My first reaction was curiosity. My second was the one every physician is trained to have: Where's the evidence? When doctors adopt something for themselves, it's worth paying attention. But it's not the same as proof. So I went back to the research to answer the question my patients keep asking me: Is applying estradiol to your face beneficial, or is it hype? The honest answer is that it's both. Here's how to tell the difference.