Yep, biotin is great stuff. Unfortunately for some, it can cause acne breakouts, so be warned! I am acne prone, and I want to try biotin but I'm fairly certain I'm not going to have good results.
My mom was losing her hair rapidly, and biotin was the only thing that helped her. Granted that is not always the case for everyone. Some people may have a medical condition that is causing it, or male pattern baldness.