Biotin runs ads one of the most supreme  multivitmain when it comes to growing hair out. You will need approximately 2500mcg of Vitmain B complex or more preciesly  biotin to help Grow Your Hair. Biotin Is a powerful B vitamin known to help grow long hair. recent and old studies have repeatedly shown that 2500mcg of biotin will and can  help grow. yoru mane. You can also use prenatal pills which is essentialy a powerful multivitamin which provides your hair with all the nutrients they need to stop hair loss and regrow hair either way a supplements is necessary to grow hair