Hi,
I took GNC Ultra Nourishair and GNC Hair, Skin & Nails for 3 months without any skin breakouts.
However, I no longer take them, I take biotin, MSM, Flaxseed oil, and a Muliti-Vitamin. The Biotin took the longest for my body to adjust too. For the first 2 days, after I would take the Biotin with food, I would get really light headed. Then that went away a week later, then later on I started having acne!! I'm now a month on these pills and my skin is fine.
I later found out that that dosage was too high and I should've started out low (like 1,000mcg). I also wasn't drinking enough water either.
And it also took time for my body to adjust to the changes.