A humectant is a hygroscopic substance that has a molecular structure with several hydrophilic (water loving) groups, such as hydroxyl groups (OH) and/or amine groups (NH2). There needs to be enough NH and OH groups on the molecule to counteract the nonpolar parts (i.e. hydrocarbon portion), allowing the overall molecule to be polar enough to attract water. The OH and NH groups hydrogen bond with water, essentially “grabbing” it and holding it on the skin. Humectants slow water from evaporating and therefore keep the skin hydrated. Examples of humectants include glycerin, amino acids, peptides, urea, and hyaluronic acid.