I've never had a keratin treatment and I'd like to start with this product. For those that have used it before, have you had any problems with excessive shedding, breakage, thinning, or limp hair that never regains its curl pattern?

My hair is type 4a, medium strands and very thick/dense. I'd like to keep the thickness and not have to deal with frizz or reversion issues when it's straight. I still want it to look like afro hair when not straightened, but a bit of curl loosening(no looser than a kinky-textured 3b) wouldn't be a deal-breaker.

Would this be the best product to achieve these goals? If not, any other recommendations are very much appreciated! Thanks!