Betaine

What it does

A naturally occurring amino-acid derivative, usually sourced from sugar beet, that holds water in the skin and helps skin cells cope with dehydration.

Benefits

A gentle humectant that hydrates without stickiness. As an osmolyte it helps cells hold on to water under stress, and lab work suggests it supports the tight junctions that keep the barrier sealed.

Concerns & Risks

None well established. Not to be confused with cocamidopropyl betaine, a cleansing surfactant with a quite different irritation profile.