Glycerin

Description

Glycerin is the most widely used humectant in skincare and cosmetic formulations. A naturally occurring sugar alcohol, it attracts and binds water to the stratum corneum, improving skin hydration, plasticity, and barrier function. At concentrations of 3–10%, it reduces transepidermal water loss (TEWL) and has been shown to accelerate barrier recovery. Glycerin also modulates aquaporin-3 (AQP3) channels in keratinocytes, facilitating water and glycerol transport across cell membranes.

Mechanism of Action

Glycerin acts as a hygroscopic humectant, drawing water from the dermis and the environment into the stratum corneum. It integrates into the intercellular lipid lamellae, maintaining the liquid crystalline structure essential for barrier homeostasis. Glycerin also upregulates aquaporin-3 expression, enhancing transepidermal water transport and keratinocyte differentiation. At physiological concentrations, it serves as an endogenous moisturizing factor and supports corneocyte desquamation.

Indications

• Dry skin / xerosis
• Eczema / atopic dermatitis
• Irritant contact dermatitis
• General skin hydration
• Barrier repair
• Sensitive skin care
• Post-procedural moisturization

Available Concentrations

Side Effects

• Rarely irritating at standard concentrations (≤10%)
• At very high concentrations (>50%), may paradoxically draw water from deeper skin layers in low-humidity environments

Pregnancy Category

Not classified (generally recognized as safe — GRAS)

Found In

Cosmetics containing Glycerin

Related Conditions