What does glycerin do for skin?

What glycerin does in a moisturizer

Glycerin draws water into the stratum corneum, the outermost layer of skin. Emollients soften and smooth skin, while occlusive ingredients form a surface layer that slows water loss. Moisturizers are a group project: glycerin handles water, while other ingredients have their own jobs.23

What you can expect

A moisturizer containing glycerin can support hydration and help reduce dryness, scaling and itch. In one seven day trial, 60 people with dry skin washed their forearms with soap four times a day and applied a moisturizer to one forearm after washing. The moisturizer contained glycerin alongside paraffin, silicone, fatty ingredients and beeswax. The moisturized side had a smaller immediate increase in water loss and skin pH after washing, with improved friction and redness compared with the soap only side. The tested cream had a supporting cast, because glycerin did not arrive alone. The trial shows what the complete moisturizer did in that hand washing setup; it does not isolate glycerin's share of the result.34

How to use a moisturizer with glycerin

1. 1Look for glycerin or glycerol on the ingredient list. Both names are used for this humectant.
2. 2Choose the texture for your skin and dryness. A cream or ointment is a reasonable starting point for dry skin; oily skin can consider a lighter gel or skipping moisturizer.
3. 3Apply the moisturizer to damp skin right after bathing, when it can help hold on to water already in the skin.

Frequency depends on how dry your skin is. Slightly dry skin may need only a light moisturizer at night, while very dry skin may benefit from a greasy occlusive moisturizer every couple of hours. Moisturizer benefits are strongest in the first six hours after application, and regular use two to three times a day may be needed to maximize them. Those are general moisturizer timings, not a glycerin dose.3

Does glycerin suit every skin type?

Glycerin does not determine whether a moisturizer feels light or rich. Gels tend to feel lighter than creams, while ointments are the most occlusive and useful for very dry, thick or scaly areas, though some people find them too greasy. Rich occlusive moisturizers can aggravate acne, so that warning is about the formula, not a proven glycerin specific effect.35

People with sensitive skin, including skin affected by atopic dermatitis or rosacea, can experience burning or stinging from moisturizers. If irritation is brief, the product can generally continue to be used; stop using it if an allergic skin reaction develops. Fragrances and some preservatives can trigger skin allergy in people who are sensitized.3

If dry skin becomes painful, cracked, bleeding, stinging or very irritating, see a dermatologist. Excessive dryness can have an underlying skin condition that needs its own treatment.56