I just started taking GNC biotin a few days ago. I used to use that first last year and never had any problems with breakouts.
Earlier this year I used a brand from Wal-Mart (I'll see if I can remember the name) and I did HORRIBLY. I broke out and everything...within a day or two.
I have not had any problems right now with the GNC Biotin.
ETA: The brand is called Spring Valley. Those were tablets and the GNC brand are capsules. The GNC brand made my eyelashes grow really long too.