Could some shampoos be irritating and cause clogged follicles/hair loss?

Clogged Follicles: As a hair transplant surgeon, i can tell you that is nearly impossible to for a hair follicle to become 'clogged.' while it is true that after hair growth ceases at the follicle, it does fill with sebum, however, this is not the cause of the hair loss, it is merely the result of the follicle not producing hair anymore. Certain shampoos can cause irritation, which diminishes hair growth, however.