I have a confession. When I see sodium lactate on an ingredient list, I don’t get particularly excited. Sodium hyaluronate? Ooh, fancy. Ceramides? Very serious. Very skincare. Niacinamide? Everyone’s favorite overachieving B student. Sodium lactate? That sounds like something you’d be given intravenously after collapsing dramatically in a hospital corridor while a nurse shouts for a crash cart. But sodium lactate is actually a rather interesting cosmetic ingredient. It hydrates. It helps control pH. It occurs naturally in the skin. It can help support certain preservation systems. And it has a surprisingly long history that begins, appropriately enough, with sour milk. So let’s