Initially, this topic scared the living daylights out of me (pre-op). A year and a half later, I'm still very loyal to Biotin and I don't plan to stop. My hair is so thick, if there was hair loss, I don't see it. I've recently read Biotin taken in the dosage of 10,000 can somewhat be harmful to your health. I'm now starting to alternate 5,000 one day and 10,000 the other. All is still great!