I have taken biotin off and on. I started taking it again a couple months back. I always stopped taking it b/c I didn't think it was doing anything until I realized this last time it works the most for your new growth. I do not take a high dose of biotin only 300 mg. I also take a multi-vitamin and since I don't eat a lot of fish or nuts I take omega-3. My nails are also longer and stronger. I am not going to stop taking it this time around.