Honestly, I knew it was working when my nails grew super long. It's literally never been able to grow past a certain point my whole life, but I looked like I had extensions! My hair and skin have definitely gotten better too. I've had collagen from other brands that either don't taste as good or just don't work as well (I use the marine collagen). I've sworn by this brand and put so many friends onto it, I actually wish there was a referral code! Matcha (tastes like matcha you'd get a tea house), Strawberry and Chocolate are my favorite flavors out of all that I've tried.