What is Biotin Good For? Benefits, Sources, and Deficiency [Video]

Brittle nails, fraying split ends, dull skin: These cosmetic details may encourage you to ask your doctor about starting a biotin supplement. But what exactly is biotin, and apart from potentially making your hair glossier, has science indicated it provides other health benefits?

Biotin, also known as B7, is a water-soluble vitamin, meaning your body does not store significant quantities of it. So, if you were to take a biotin supplement that exceeded your body’s needs, you’d probably excrete the remainder through urine. “Our bodies do not produce biotin directly, but bacteria in our digestive system do synthesize it,” says board-certified dermatologist and dermatologic surgeon Tyler O. Vukmer, D.O.

The authors of a 2023 study on biotin deficiency and intestinal dysbiosis explain that microbiota (AKA bacteria) in the gut “depend on biotin for growth and survival.” In other words, gut bacteria (primarily located in the large intestine) create biotin out of necessity on its own.

But, for some people, …