Biotin supplements are available alone, combined in a supplement with B vitamins, or included in a multivitamin. If you're experiencing hair thinning or hair loss, biotin may assist in regrowth. Biotin is found in many foods and beverages, including milk, carrots, salmon, and nuts. It can also be taken as a supplement if needed. This medication is best taken on an empty stomach 1 hour before or 2 hours after meals.