Humectants

Humectants are substances that attract and retain moisture. They are hygroscopic compounds used to keep products moist, regulate water activity, and prevent desiccation of foods, cosmetics, pharmaceuticals, and other materials. Humectants work by binding water molecules through hydrogen bonding and, in some cases, by creating a local environment that slows water loss. They can draw water from the surrounding air at higher humidity, helping to maintain texture, softness, and stability.

Common humectants include glycerol (glycerin), propylene glycol, butylene glycol, sorbitol, xylitol, and trehalose. Other examples are diacetylated sugars and certain salts such as sodium lactate. In cosmetics and personal care, glycerin and propylene glycol are widely used to moisturize skin and hair. In foods, these compounds help retain moisture, improve texture, and extend shelf life. In pharmaceuticals, they can stabilize formulations by maintaining moisture.

Uses span several industries. In the food industry, humectants prevent drying and staling. In cosmetics, they improve hydration and skin feel. In pharmaceuticals, they aid in tablet formulations by preserving moisture and facilitating processing. In construction and textiles, humectants can help control moisture content to reduce cracking and warping, and in tobacco and wood products they help maintain a predictable moisture level.

Safety and regulation vary by compound and application. Many humectants used in foods are regarded as safe and are approved as food additives (GRAS in some jurisdictions). Some can cause laxative effects if consumed in large amounts, and sensitive individuals may experience irritation. Products should use humectants in accordance with applicable safety guidelines and labeling.