Does shampoo cause hair loss?

“Normally, between 40 and 100 hairs are shed daily on a non- shampoo day; twice as many are shed on days when the hair is shampooed.”  Does that mean we shouldn’t shampoo?

Hair that is shed is not coming out because you shampoo your hair, it comes out because it is either going through its normal telogen cycle or you are losing it from miniaturization or genetic factors. Not shampooing your hair will make no difference in your overall hair volume or hair density across the scalp.  Brushing it roughly will pull out miniaturized hairs so I generally tell men with hair loss to use a wide toothed comb