Curl Junkie BeautiCurls protein?
 

My hair is protein sensitive and very dry, and although BeautiCurls leave-in is protein free it contains Nettle leaf extract and horsetail leaf extract. I heard these can act like proteins, so is this leave-in safe to use, or will it dry out my hair even more?

All you can really do is try.

Fwiw - my hair loves virtually anything CJ. I'm protein sensitive so I don't slather on a protein product when I don't need it but my hair loves CJ. Also, aloe can act as a protein and it does in my hair but my hair actually tolerates it fairly well - you might find these two ingredients work fine for you.