Our Biotin formula provides you with 1000 mcg of biotin per tablet. An essential B Vitamin which is beneficial to skin, nail and hair health. For additional formula information, view the Supplement Facts panel. All Windmill supplements are manufactured in the United States in an FDA-inspected facility whose GMPs (Good Manufacturing Practices) are independently verified by qualified certification organizations. Free of artificial colors, flavors and preservatives, Windmill is a trusted name that has been providing America with quality supplements for over 40 years.