On the surface, this sounds like a "duh" question. I could see a company testing a volumizing shampoo on someone with thin hair. At the same time, would that person have 4b or 3a thin hair? Would it make much difference? Just curious.
***I do already know that some products that work on 3b hair may work on my 4b hair and vice versa.
***I do already know that some products that work on 3b hair may work on my 4b hair and vice versa.