Betaine

Betaine is a humectant (hydration-optimizing) ingredient that may be plant-derived or synthetic. It also occurs naturally in skin and the body.

It’s known as an osmolyte, an ingredient that helps skin adapt to moisture losses and gains, essentially working to balance skin’s hydration. Betaine is often included in cleansing blends because of its gentle soothing nature that helps offset the potential irritating effects of detergents. It’s also used as a hair conditioning ingredient.

Newer research indicates betaine shows promise as a topical ingredient to visibly correct uneven skin tone. More studies are needed to confirm this effect, but so far, the results look encouraging.