My hair is on the thinner and weaker side, so when my friend recommended hair collagen, I honestly didn't believe her, lol. But she told me to just try it once, saying she used to take the Evercollagen one and offered me two bottles since I ordered a lot. So I started taking it, and lately, when I tie my hair up, it feels like it's gotten a bit thicker, so once I finish this, I'm planning to buy some for myself, lol.