I have thinning hair and was listening to Dr radio on Sirius XM and they recommended Biotin and Monioxidil. Which started taking and using and my hair is growing back in and getting thicker after a few months!GNC has Womens Hair Skin Nails Vitamins. They have 1000 mcg Biotin in them. Suppose to be good. I am planning on getting a bottle for myself soon.