Sodium lactate is found as a 100% concentrated powder or 60% concentrated liquid. It’s used as a humectant, which is to say that it draws water from the atmosphere to our skin or hair and it works as a hydrating ingredient.
It has been found to improve the barrier properties of our skin (in studies, there is a decrease in the trans epidermal water loss, which is a good thing), it is believed to stimulate ceramide synthesis in the skin, and it increases the plasticity of our skin. It also acts as a mild AHA, which can help reduce “the look of fine lines and wrinkles”. It has a really high water holding capacity (meaning it’s a very effective humectant), and it is about 1.5 times more effective in this department than glycerin.
Because this is an electrolyte, be wary of using it with sodium polyacrylates or any other ingredient that doesn’t like electrolytes or salts.