Oils accomplish a lot for your hair: They can help strengthen and fortify the hair with natural fatty acids and nutrients. They can protect your hair from UV and free radical damage with antioxidants. They can condition the scalp and damaged strands. They help impart a slick layer of shine.
And for frizz? Well, they can help seal down the cuticle, which is what leads to frizzy hair in the first place. Not to get too into the science, but the cuticle is the outermost layer of the hair shaft. The cuticle layer is made of tiny shingle-like platelets of keratin that overlap. When those shingles lift—due to humidity, damage, or just naturally—your hair separates, thus causing frizz. Oils (and other leave-in products) have the ability to smooth and hold these little platelets down throughout the day.
While there are plenty of natural, at-home options you can reach for—a hairdresser favorite is argan oil.
“It’s great for many conditions, especially dry, damaged hair because its trove of fatty acids locks moisture into the hair follicle,” says Bindiya Gandhi, M.D., an American Board Family Medicine physician and mbg Collective member. Even though it’s not actually possible to reverse split ends, there are some solutions that can help improve the appearance of them. According to hairstylist Lucia Casazza, using argan oil can help transform the appearance when used as a mask. “When hair is severely overprocessed, where ends appear fragile and gummy when wet, I would use argan oil as a mask under a cap,” Casazza suggests. “There are also times when I simply apply it as a leave-in treatment before and after a blowout for a clean, polished look with silky, smooth ends.”