system
Given the following post, respond as if you're commenting on Reddit:
human
Can "buildup" on scalp actually cause hair loss?

There are tons of products marketed towards people with thinning hair that claim to function by cleansing the scalp of buildup and creating a healthy environment for hair growth. This is because they allege that buildup can essentially kill your hair follicles if it gets bad enough. Is this scientifically sound, or a bunch of cosmetology marketing bullshit?
gpt
I can't find anything supporting this notion. Not to say it isn't the case, but it just doesn't seem to be very well studied. 

Androgenic alopecia (male pattern baldness) *is* well studied, and its mechanism is not based on scalp environment. 

There are several different known mechanisms that lead to balding, but the only one that deals with things outside of the body is traction alopecia.