My hair HATES it, I give up. I'm not joking: if I put yogurt in my hair, or an avocado for 5 minutes I'll have to pick a pair of scissors and cut here and there and I have to baby it back for a month. Even collagen in products is pretty scary for my hair.
Aminoacids (aloe, tresemme naturals, aubrey organics rosa mosqueta),ceramides (wheat germ oil) are all I need if I want a little pick me up, in a different way than protein does. I have no idea why.
I keep noticing that many people who have thick strands like me hate protein, and people with fine strands seem to love it, but I may be wrong.