A naturally occurring polyol that helps improve stratum corneum hydration and skin feel. According to 2014 FDA VCRP data, glycerin was the third most frequently reported cosmetic ingredient, appearing in 15,654 product formulations. Its hydration performance depends on concentration, formulation, and environmental humidity — often paired with occlusive ingredients for best results.
A powerful moisture-binding agent that attracts and retains water from the surrounding environment to help keep the skin surface hydrated and plump. It also helps improve product texture and feel while providing gentle skin conditioning benefits. This ingredient has an excellent safety profile and is generally well-tolerated, though individual tolerance may vary.
Glycerin (CAS No. 56-81-5) is a simple polyol compound with three hydroxyl groups and a molecular formula of C3H8O3. It is naturally occurring in all animals and plant matter as glycerides in fats and oils. For cosmetic use, natural glycerin is obtained as a byproduct in the conversion of fats and oils to fatty acids or fatty acid methyl esters (e.g., soap-making or biodiesel production). Synthetic glycerin can also be produced from propylene. It is completely miscible with water and has solvent properties similar to water and simple aliphatic alcohols, making it an incredibly versatile formulation ingredient.
According to 2014 FDA VCRP data, Glycerin is the third most frequently reported ingredient in the cosmetic database — after water and fragrance — appearing in 15,654 cosmetic products. Observed industry concentrations reach up to 79.2% in leave-on products and 99.4% in rinse-off products (CIR, 2014); these are maximum reported values, not recommended or regulatory limits. The FDA considers Glycerin GRAS (Generally Recognized As Safe) for food use, and it is also approved as an OTC drug for ear wax removal, skin protection, and oral care.
As a humectant, glycerin attracts and binds water from the surrounding environment to the skin surface. Its three hydroxyl groups form hydrogen bonds with water molecules, providing lasting hydration without a heavy feel.
By maintaining optimal moisture levels, glycerin reduces roughness and flakiness. It improves the appearance of fine lines caused by dehydration, giving skin a visibly smoother, more even texture.
Glycerin strengthens the skin's natural moisture barrier, reducing trans-epidermal water loss (TEWL). A well-hydrated barrier is more resilient against environmental stressors and irritants.
Generally well-tolerated by most skin types, though individual sensitivity may vary. The CIR report confirmed no irritation at 50% concentration in subjects with dermatitis (n=420). Also acts as a viscosity modifier, improving product feel and spreadability.
Generally suitable for: Most skin types — dry, oily, combination, sensitive, and acne-prone. Individual tolerance may vary.
The CIR Expert Panel (December 2014) concluded that glycerin is safe as a cosmetic ingredient in the practices of use and concentration described in their safety assessment. EU approved with no restrictions. FDA GRAS for food use.
In very low-humidity environments, glycerin (like all humectants) used alone may feel less effective at maintaining skin hydration. Pair with an occlusive moisturizer (ceramides, squalane, or petrolatum) to lock in hydration.
At very high concentrations (above 30%), glycerin can feel sticky on the skin. Most effective consumer products use 2%–10% for optimal feel and efficacy.
The CIR Panel noted that glycerin derived from the Jatropha plant may contain phorbol esters. The FDA advises that glycerin from this source should not be used in cosmetics. Conventional impurity tests may not detect these toxins.
The CIR 2014 report reviewed multiple reproductive and developmental toxicity studies in animals. Oral NOAEL for maternal toxicity and teratogenicity: 1,310 mg/kg/d in rats, 1,280 mg/kg/d in mice, and 1,180 mg/kg/d in rabbits — with no fetal abnormalities observed in any species. No adverse effects were seen in rats administered 20% glycerin in drinking water throughout gestation and nursing; the F1 generation reproduced normally. Note: these findings are based on animal studies; no large-scale human clinical trials on topical glycerin during pregnancy have been published. Topical glycerin is generally considered safe during pregnancy, but always consult your healthcare provider.
Double humectant power: HA is known for its exceptional water-binding capacity while glycerin provides steady, long-lasting moisture. Complementary humectants that work well together.
Niacinamide strengthens the skin barrier while glycerin supplies hydration. Complementary mechanisms with no conflict.
Occlusive ingredients that seal in the moisture glycerin attracts. The ideal partner to prevent water loss, especially in dry climates.
Glycerin counteracts the dryness and peeling retinol can cause. Apply retinol first, then follow with glycerin-based moisturizer as a buffer layer.
Without an occlusive seal, glycerin used alone may feel less effective at maintaining hydration when humidity is below 40%. Always follow with a cream.
Pure glycerin (above 30%) can feel sticky and may not absorb well. Dilute or choose products formulated at 2%–15% for best feel and efficacy.
Found in 34,603 product variants in our database. Here are some well-known options:
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