What does glycerin do in a moisturizer?

How does glycerin help keep skin hydrated?

Glycerin helps retain water in the stratum corneum, the outermost layer of skin. Other parts of a moisturizer do different jobs: emollients smooth and soften the surface, while occlusives form a protective layer that reduces evaporation. Mineral oil, petroleum jelly and dimethicone are examples of occlusives. Attracting water and slowing its escape are complementary jobs, so the whole formula matters.1

What kind of glycerin moisturizer should you choose?

Glycerin is a useful ingredient to look for when your skin is dry. In cold, dry weather, a lighter facial lotion may not provide enough protection; a cream or balm can be a better choice. For dry body skin, thicker creams and ointments typically provide more moisture than thinner formulations.2

Does glycerin help eczema as well as ordinary dryness?

Glycerol containing moisturizers have helped people with eczema notice skin improvement compared with a placebo or the cream base without glycerol. Glycerol is another name for glycerin. The improvement in clinician rated eczema severity was small, below the threshold considered a meaningful clinical change. Think of glycerin as hydration support, not a replacement for prescribed eczema treatment. Moisturizers used alongside active treatment have reduced eczema severity and flares more effectively than active treatment alone.3

In a trial involving 49 adults with eczema, a glycerol cream performed better on skin barrier measures than a simple paraffin cream, but a cream combining urea and glycerol performed better still. Those differences concern the tested creams, not every product containing those ingredients. Choose the whole moisturizer, not just the ingredient name; the front of the bottle is not a treatment plan.4

How should you use a glycerin moisturizer?

1. 1Apply your moisturizer immediately after bathing, while skin is still damp, to help retain existing moisture.
2. 2Adjust frequency to dryness. Slightly dry skin may need a light moisturizer at night; regular application two to three times a day can help maximize benefits.
3. 3In the morning, apply sunscreen after moisturizer. Choose broad spectrum, water resistant sunscreen with SPF 30 or higher.

How long does it take to work?

Moisturizers have their greatest therapeutic effects in the first six hours after application, which is why regular use matters. The adult eczema trial assessed the creams after four weeks of twice daily use. That is a useful timeframe for the tested formulas, not a deadline for every glycerin moisturizer to repair dry skin.14

What if your moisturizer irritates your skin?

Sensitive skin can sting or burn with moisturizers. Fragrances and preservatives can also cause contact allergy, so a reaction does not automatically identify glycerin as the culprit. Stop using a moisturizer if contact dermatitis, an inflamed skin reaction, develops. Suspected contact allergy can be investigated with patch testing.1

Excessively dry skin needs treatment, especially when itch or pain persists. A dermatologist can select the right mix of moisturizing ingredients and check whether an underlying condition needs treatment too. Some people need a prescription moisturizer. If you already have a treatment plan, apply the selected moisturizer as often as prescribed rather than replacing it simply because another bottle lists glycerin.5