What are they: Humectants are often used in hair products (pomades, leave-ins, gels, etc) as a moisturizer for dry, brittle strands. They attract moisture to your hair follicles.
Why you should care: When there’s already moisture in the air (hello, humidity!) and you use a product with humectants, you could be attracting too much moisture, leading to a frizzy, shapeless style.
What to look for: Some products tout themselves clearly as anti-humectant. If you’re not sure, check the ingredient list—some commonly used humectants include: propylene glycol, collagen, glycerin, sodium PCA, and glycogen. Either look for products that don’t have these or at least find ones that have them further down on the ingredient list, which means they’re less potent.