4. Eggs: Eggs are an excellent source of those aforementioned omega-3s, and they are also contain biotin (which many people trying to grow their hair take in supplement form). But, just so you’re aware, it’s not the egg white that will make your hair long and beautiful, it’s the yolk. Eating too many egg whites can actually block the absorption of biotin into the body, causing a depletion of this micronutrient.