Hi,
There is no medical evidence that biotin is useful for hair growth in healthy patients. Its only known the patients with vitamin deficiency can have alopecia but te reason is still unknown and there is no evidence that for healthy patient it helps.
Hair loss in healthy patient like male and female pattern hair loss works on a different etiology and treatments to slow it down have to come from more medically sound basis like DHT blockers, or minoxidil to incresae blood vessels supply in the scalp which by the way is medically proven and FDA approved.
So for Biotin supplement, its a case of if you wish to try it and it works then continue, if it doesnt, then do bother. And dont take excessive amounts.
Hope that helps