While he acknowledges that the role biotin plays in hair growth is unclear, dermatologist Dr. Richard Scher claims that this vitamin does improve keratin infrastructure. He also acknowledges that biotin supplements may help in some cases of hair loss and reverse the process along with making the nails less brittle and weak, notes an article in The Huffington Post.
In the same article, dermatologist Dr. Susan Stuart also acknowledges that the B complex vitamins in biotin have significance for metabolism, which helps the body process energy and transport carbon dioxide from the body's cells. Freelance hair stylist Giulia Heiman in an article on About.com explains that consistent everyday use yields the best results, which usually manifests in about one month.
Dr. Scher recommends a dosage of biotin of 2.5 milligrams, but Heiman recommends 5,000 micrograms per dose. Neither Scher nor Heiman knows whether this dosage offers the full effect for biotin. However, taking more than the recommended dose may contribute to an overdose. Heiman warns against taking biotin supplements for people trying to become pregnant or already pregnant and also notes that biotin decreases the effectiveness of some heart and anti-seizure medications. Dr. Stuart names several signs of biotin overdose including slower release of insulin, skin rashes, lower vitamin C and B6 levels and high blood sugar levels.