I love biotin, it's my stable vitamin. When nothing else worked Biotin does.
It requires a lot of patience i'd say. I saw results after a couple of months.
I wouldn't recommend you start on 1k or more if you hadn't had it before or had that high of an mcg.
Regardless of how much water you're drinking, if it's too much for your body all at once you'll break out. If you break out or feel ill, lower your mcg.
I started on 300...i know what you're thinking "
aint nobody got time for dat" but I took that for a month, moved up to 1k for a month or so, I just finished the bottle then moved up to 2k then 4k (two of the 2k pills), then 5k and then 10k. Now i'm taking hairfinity and mineral rich so I don't take the biotin pill cause there's a lot of it in those.
There is a clear difference in my hair from when the biotin started kicking in cause it makes your hair thicker and stronger, so it's harder to break of, meaning you retain more length.
Don't try and start on a higher msg and risk the breakout thinking if you drink water you'll be fine.
Don't be off put by the amount of time it'll take, the time will pass anyway. You can either have thicker hair in a couple months or still be wondering what biotin will do for you.