Biotin is a type of
Vitamin B7. It is one of the various Vitamin B complexes. It is safe and when in excess it excreted through urine as it a water soluble vitamin. Hair supplements that are usually prescribed to patients contain not only biotin but also
calcium pantothenate, copper, zinc, selenium, folic acid and few more components. These tablets are safe and you need not worry about side effects. There are various brands available in the market like Biograve, Adgain, keraglo eva(for females), biograce, VB7 forte, etc. There is only slight difference between these different brands and you can take any one of these. However, just supplements will not be enough if you have hair loss . You will need to have a Dermatologist examine your scalp properly with a trichoscope and decide what other definite treatment would benefit you more. To know more about hair loss you can read my blog - http://drshanshanwalmd.blogspot.in/2017/05/going-bald-is-it-because-of-hair-loss.html
Next Steps
I would recommend getting a proper evaluation by a qualified dermatologist before self medicating