For all their benefits, natural oils can also cause unwashed hair to inch towards greaseball territory, particularly if you have fine hair. "What happens when people stop washing their hair hugely depends on their hair type, and for some people, it can leave hair oily and flat," says Cairns. The good news: No matter your hair type, it gets better! (If you do have thin hair, try these 10 gorgeous and simple hairstyles.)
"When you strip the oils from your scalp and hair, your scalp will overproduce oil. But over time, it will begin to produce less," says Cairns. "The first couple weeks may be difficult, but your scalp will adjust." While your scalp is "in training," Kinney suggests camouflaging any greasiness by pulling your hair into a sleek ponytail or topknot on the day(s) after a wash.