Does biotin make your hair longer? The bottom line. There’s no strong evidence to support using biotin for hair growth or to prevent hair loss in people without a deficiency. Because hair thinning and poor hair growth are sometimes associated with a biotin deficiency, correcting a deficiency can help restore hair growth in some people.
How much biotin should I take for fast hair growth? 2 to 5 milligrams
How long does biotin take to make hair grow? It takes months to see results on biotin. According to The Journal of Clinical and Aesthetic Dermatology (source), biotin takes around 90 days to begin to work. Contrary to some of the claims you may have heard, biotin is not an overnight remedy that will magically give you 5 inches of hair growth in 24 hours.