Dietary Supplememt. 21st Century®... For a healthier Future. 10% Free. Maximum Strength. An Essential B-Complex Vitamin for the Normal Metabolism of Carbs, Protein & Fats* Biotin is one of the B-Complex vitamins. Biotin helps support healthy hair, skin and nails and is an essential nutrient for the normal metabolism of carbohydrates, proteins and fats.* Unconditionally guaranteed for purity, freshness and label potency. No sugar, yeast, preservatives, artificial flavors or colors.