I live with pets, finding hairs in food around here is a fact of life. I don't bother to pick the tiny ones out. Extra fibre, right?
As for hair in drugs, what sort of hair depends on if I'd care or not? Just your basic who-knows-what fuzz? Pet hair? I don't care. 10 inch long head hair all knotted around your weed? Bordering on gross. Wad of pubic hair mixed into your pills? NOT COOL.