The biotin 5000mcg plus BioPerine is exactly what I needed—my nails stopped splitting within two weeks. I just wish the capsules weren't so large, but downing them with orange juice does the trick.
I've been taking these for about three weeks now and the BioPerine really seems to make a difference—my body actually feels like it's absorbing the collagen instead of just passing it through. My nails have stopped peeling at the tips, which is the first real change I've noticed from any supplement.
The capsules are easy to swallow and don't leave that fishy aftertaste I've gotten from other marine collagen—the BioPerine is a nice touch since I actually feel like it's working now. My skin's been looking noticeably plumper around my eyes, which is the main reason I bought it.