Skim through

What it does: antistatic, conditioning, moisturizer/humectant, viscosity controlling

The science

A sugar beet derived amino acid derivative with protection and moisturization properties. Betaine improves shine by helping maintain the integrity of the cuticle surface. As an osmolyte, it also possesses the ability to penetrate the stratum corneum of the scalp, where it can optimize moisture in the skin cells and follicles, positively impacting the health of the scalp and contributing to healthier hair.

It is also a natural osmoprotectant, meaning that it attracts water away from protein surfaces and thus protects them from denaturation and increases their thermodynamic stability. It gives sensorial benefits to the formula and when used in cleansers, it helps to make them milder and gentler. 

Benefits for your hair

Promotes hydration

The water retention capability of betaine makes it an ideal ingredient for hair care products. It improves the hair feel and the ease of wet/dry combing.

Prevents irritation of scalp

Betaine is used as a non-irritating ingredient and may help soothe inflamed sensitized skin. Betaine is less irritating than water and helps to maintain the skin’s natural barrier, protecting the skin from water loss, allergens, and bacteria. A healthy skin barrier is important for preventing irritation and sensitivity in the scalp. 

TLDR 

The addition of betaine to hair care products gives the hair strength and hydration, as well as making the hair shiny and more elastic.