Glycerin, also called glycerol, is one of the most common moisturizing ingredients on any label. It draws water into the skin's surface and helps the barrier hold on to it. In controlled trials at 20%, it improved hydration in very dry skin and stung less often than a cream with urea and salt.
- Helps with
- dry skin, tightness, flaky patches, winter dryness
- Evidence
- Strong. Randomized trials and long use support its moisturizing effect; most trials studied people with very dry or eczema-prone skin.
- Typical strength
- 20% in both controlled trials cited here
- Works well with
- ceramides, hyaluronic acid, occlusive moisturizers
What does glycerin do for skin?
Glycerin is the quiet workhorse of moisturizers. It is for the tight feeling after a hot shower, flaky patches on the shins in winter, and cheeks that look rough when the heating is on. It pulls water into the outer layer of skin and helps keep it there, so skin feels softer and looks less flaky.
Skin uses glycerol naturally. A 2008 review notes that “endogenous glycerol plays a role in skin hydration, cutaneous elasticity and epidermal barrier repair”, meaning the glycerol skin makes itself helps with moisture, bounce and barrier repair. The same review lists protection against irritation and help with winter dryness among its effects.
Does glycerin work for very dry skin?
Yes, in controlled trials. In a double-blind study of 197 people with very dry, eczema-prone skin, a cream with 20% glycerin was compared with its plain base and with a cream containing 4% urea and 4% salt, used at least once a day for 30 days. Glycerin and urea improved dryness equally, but stinging was reported as moderate or severe by 10% of the glycerin group versus 24% of the urea group.
In another study, 24 people with eczema-prone skin used a 20% glycerol cream or a placebo twice a day for 4 weeks. The glycerol cream raised skin hydration and improved barrier function; it did not change redness or overall severity scores more than the placebo.
Why is glycerin in almost every moisturizer?
Because it does a basic job well, and in the trial above it stung less often than the comparison cream. Healthy skin depends on holding water in its outer layer; when that fails, skin turns dry and flaky, as a review on moisturization explains. Glycerin is one of the simplest ways to help.
How long until you notice a difference?
In the trials above, measured improvements in hydration showed over 4 weeks and 30 days of use.
How do you use glycerin?
Look for it in a moisturizer or serum and apply to slightly damp skin after washing, then seal with a cream. For body dryness after showering, see why skin feels so dry after a shower. Lips are a special case; see why lips get drier than skin.
Who should be careful with glycerin?
Very few people. In the 197-person trial, the 20% glycerin cream caused less stinging than the comparison cream. As with any product, a new formula can contain other ingredients that bother sensitive skin.
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- Fluhr JW, Darlenski R, Surber C. Glycerol and the skin: holistic approach to its origin and functions. Br J Dermatol. 2008;159(1):23-34.
- Lodén M, et al. A double-blind study comparing the effect of glycerin and urea on dry, eczematous skin in atopic patients. Acta Derm Venereol. 2002;82(1):45-7.
- Breternitz M, et al. Placebo-controlled, double-blind, randomized, prospective study of a glycerol-based emollient on eczematous skin in atopic dermatitis. Skin Pharmacol Physiol. 2008;21(1):39-45.
- Rawlings AV, Harding CR. Moisturization and skin barrier function. Dermatol Ther. 2004;17 Suppl 1:43-8.
Editorial content, not medical advice.