Gather ’round, beauty junkies, because today we’re talking about the ingredient you probably ignore more than a Terms & Conditions page: water. Yep. H₂O. Aqua. The stuff coming out of your faucet while you stand there contemplating whether buying another $68 serum is technically a responsible financial decision. Water is so boring that we barely think of it as a cosmetic ingredient. Flip over a bottle of cleanser, moisturizer, serum, shampoo, foundation, or basically anything that resembles a liquid, though, and there it is. Often sitting right at the top of the ingredient list like it owns the place. And, honestly?