i've noticed that my hair is losing it's curl! i don't know if this is caused by the NBE or not, but i know that a change in hormones can have an effect on your hair. my hair turned curly when i got my period around 12 and i hated it at this time. but now i love my curly hair and i'm sad that i'm losing it!! it hasn't gone bone straight or anything, just has less curl to it these days. it could be a number of things i guess.
I believe it's very likely to be NBE induced, like you many girls get curly hair in puberty. My hair is as straight as it gets and I would love if it started curling on NBE, but unfortunately it didn't, lol.
my hair went wavy-curly-frizzy as well when i was into puberty but haven't seen any changes while on herbs. they do grow faster i think, probably because of the zinc and vitamins though.
I don't know about effects NBE has on hair, but I do know that after each pregnancy (I have three children) my hair has become more and more wavy. I believe this has happened because of a change in hormones, could be a similar thing happening with you in some way. Please keep us posted to see if it is related.