Are biotin supplements effective at thickening your hair?

No, unlikely to help: Biotin deficiency is rare, but can occur in persons with genetic mutations, on long-term antibiotics or anti-convulsants, or who eat a lot of raw egg whites. There is no good evidence that this over-the-counter supplement is the magic potion to thicken hair, grow hair, or prevent hair loss. Biotin is safe to take in the usual amounts, but not in the huge doses that some websites are suggesting.

Insufficient evidenc: There is insufficient evidence that biotin helps hair loss. There is some preliminary evidence that hair loss can be reduced when biotin is taken by mouth in combination with zinc while a cream containing the chemical compound Clobetasol Propionate (olux, temovate) is applied to the skin. Symptoms of biotin def. Include thinning of the hair (often with loss of hair color), & rash.