Betaine

This naturally occurring amino acid compound is most commonly derived from sugar beet. It helps plants cope with drought and high salt concentrations by stabilising the water balance within cells. In cosmetics, it is used as an osmolyte and humectant. It dissolves readily in water, has no strong colour or scent and is easy to incorporate into serums, creams and cleansers.

Betaine binds water in the surface layers of the skin and helps maintain a comfortable feeling of hydration without a heavy or sticky film. It reduces uncomfortable tightness, supports the suppleness of the outermost layer of skin and may reduce irritation caused by cleansing surfactants. Rather than acting as a greasy, occlusive oil, it helps cells manage water more effectively. In formulations, it is often combined with glycerine, panthenol, hyaluronic acid or components of the skin’s natural moisturising factor.

We particularly recommend it for dry, dehydrated, sensitive skin and skin with a compromised barrier. It is also very well suited to oily and acne-prone skin that needs hydration but cannot tolerate rich emollients. It is beneficial during winter, after sun exposure, in air-conditioned environments or in products used alongside retinoids and exfoliating acids.

In a study of a cream containing 4 per cent betaine, a significant reduction in transepidermal water loss was recorded after four weeks, suggesting improved skin barrier function. Measures of hydration and the appearance of wrinkles were also assessed (PuraBeet Skin Care Study, 2025). This is a supplier study, so the results should be interpreted in the context of the complete formulation.

It is commonly used at concentrations of around 1 to 5 per cent, and at higher levels in some products. It is stable across a wide pH range and is generally well tolerated. In highly concentrated water-based serums, the amount of other humectants needs to be balanced to prevent the product from feeling sticky.

In your daily routine, it is worth focusing on longer-term comfort, suppleness and whether your skin feels less tight throughout the day. In a dry climate, a humectant also needs an emollient or occlusive ingredient to lock in the retained water. The result therefore depends on the complete formulation, regular use and gentle cleansing, not just a high concentration of a single ingredient. Regular application in an appropriate amount is also important.