Glycerin is a substance found naturally in the skin where it helps attract and retain water from the deeper skin layers (humectant), thereby hydrating and moisturising the skin1. Glycerin is widely used in topical products, and the glycerin found in these types of products usually comes from vegetable-based oils.
In dry skin conditions, including atopic dermatitis, water loss from the upper skin layer is linked to a reduced skin barrier function, which can worsen disease symptoms2.
A recent study of adults with mild-to-moderate atopic dermatitis found that, when used twice daily for 4 weeks, a glycerin cream (20%) was able to hydrate the upper skin layers and restore the skin barrier function (compared with a glycerin-free control)3.
The changes in skin redness and severity was not different between groups, but improved over time in both groups, illustrating the importance of using emollients in eczema.
Also in young children (2-6 years) with atopic dermatitis, an emollient with glycerin (15%) and paraffin (10%) compared to one without these ingredients improved skin dryness and hydration and the eczema severity when applied twice daily for a period of 4 weeks4.
The concentration of an ingredient is important for its efficacy, and therefore products containing the same ingredient may not necessarily have the same effect as in the studies mentioned above.
Updated: July 2017