QUESTION ABOUT BIOTIN? Please answer!!?

I want to know how much biotin is safe to take? I lost my hair from chemo a few months ago and it's growing back now and I need it to grow back as fast as it can. My hair dresser told me I should take 10,000 mcgs of biotin a day, but I did a little research and most people said that 5,000 mcgs is the safest to take in one day, but my hair dresser is very experienced, so I'm really confused. I mean it does seem like a lot and I know it's a water soluble vitamin so it probably wouldn't hurt, but would it be a waste? Would I pee most of it out anyways? Any info. is helpful.