Our Biotin formula provides you with 10,000 mcg of biotin per tablet. An essential B vitamin with Maximum Strength to help maintain healthy hair, skin & nails.? 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.