Betaines are found in both the plant and animal kingdom. Due to their chemical structure they are able to regulate the osmosis of cells. Thanks to betaines, crustaceans can live in an environment with a high salt content without their cells "dying of thirst". This also applies to hot living conditions: Plants in particular use betaines to protect themselves against the evaporation of water from their cells.

In addition to their hydrating effect, betaines have a surfactant effect: they dissolve fat-like substances and thus enable the skin to be cleaned. They are also compatible with mucous membranes – which makes them welcome even in baby cosmetics.