What is Biotin? Biotin, also known as vitamin H, is a B vitamin that plays a key-role in the body. Biotin assists in various metabolic reactions in the body, including the metabolism of fats and amino acids, production of fatty acids, and cell growth. Biotin supports the health of the skin, hair and nails as well as of the nerves and digestive tract. Promotes Healthy Hair and Strong Nails. Supports Cellular Energy Production. 100% vegetarian. Size/Form: 100 Tablets Directions: Take 1 tablet, one time daily, with a meal.