A. Probably not. Collagen, a naturally occurring protein in the body, gives skin its structure—and smooth, firm appearance. That's why plastic surgeons inject it into lips and foreheads (and other body parts) to add fullness and smooth out creases.
When consumed orally, collagen's large molecules are broken down into amino acids by the stomach. That means, in the body, those pricey supplements are the chemical twin of any other kind of protein, such as meat, eggs, nuts, beans, or dairy products.
Here's what I think: Chances are your friend's diet was low in protein, which helps skin repair itself. So the extra boost from the supplement did do her skin some good. But she would have gotten the same benefit—for a whole lot cheaper—by incorporating more protein-packed foods into her meals, like adding chickpeas or almonds on her lunchtime salad.
Ahmet Altiner, M.D., is a board-certified dermatologist, an assistant professor of clinical dermatology at Weill Cornell Medical University, and owner of UWS Dermatology & Skincare in New York City.
Check out these skin-care basics for any age.