I was on 1200 mg of it for 3 years for restless legs. It was very good for that. An added benefit was a huge reduction in migraines and trigeminal neuralgia. Unfortu.ately it caused severe dry mouth. I used every Biotine product on the market ,advised by my brother the dentist. That did not help enough and i had my front upper teeth hollow out and crumble. I now have crowns in their places, with 2 more crowns to go. Needless to say I am now off of it. Be sure to have your teeth checked regularly!