i take biotin and noticed my nails are growing absurdly fast. i have to cut them every day with toenail clippers. they would grow a centimeter a week if i didn't... (maybe an exaggeration but close) is this a concern? my hair is also getting really thick.
Biotin, a B vitamin, is taken by people who have hair thinning or loss or who have weak brittle nails that break. There is no problem with it, but your experience shows it does work! I take it for hair loss associated with lupus and found it to be helpful.