Anything that ends up being traumatic to your scalp skin can affect the ability of the hair to grow, but it has to be traumatic. DHT is traumatic. Not washing your hair, if it results in extreme inflammation and irritation from overgrowth of fungus due to not rinsing the oils and sebum for weeks and weeks can definitely lead to it. .. but its not like you're not going to realize you're causing trauma and the hair will just fall out. You'll know it if you're doing damage to your scalp. It will probably hurt, itch, etc.
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