What will happen if I take Biotin for hair growth twice a day as opposed to the recommended once a day?

You can't really make your hair grow faster even when taking biotin it promotes healthy hair growth and all that will happen is that your body flushes out any of it that is not absorbed within your system, also it has been known to cause breakouts and for some dehydration, so i would drink lots of water and cut back to the recommended dose if you have any other side effects.