Glycerin

Introduction

What is glycerin?

Glycerin or glycerol is an alcohol with multiple hydroxyl groups. It is synthesised in the pilosebaceous unit (R) and exists in the stratum corneum of the skin as part of the natural moisturizing factor (NMF) (R), a natural mixture of amino acids, lactates, urea and electrolytes that helps the stratum corneum retain water (R).

Does glycerin get absorbed?

When applied to human skin, glycerin accumulates in the entire thickness of the stratum corneum, creating a reservoir within the lipid bilayers (R). It has also been shown to penetrate the epidermis of pig skin, taking at least 30 minutes to do so (R).

Efficacy

Outcome	Grade	Effect	Evidence	Studies
Skin Hydration	B	🠩 Slight	★★★ Fair	2 studies 48 participants
Skin Smoothness	C	🠩 Slight	★★ Some	1 study 13 participants
Skin Barrier Function	C	⇧ Potential	★★★ Fair	3 studies 58 participants
Skin Sensitivity	E	– No Effect	★★★★ Good	1 study 17 participants

Mechanisms

Outcome				Grade		Effect		Evidence		Studies
Skin Blood Flow				E		– No Effect		★★★ Fair		1 study 17 participants

Latest Research

What is glycerin?

Does glycerin get absorbed?

Dermal penetration of creatine from a face-care formulation containing creatine, guarana and glycerol is linked to effective antiwrinkle and antisagging efficacy in male subjects (2011)

The influence of a cream containing 20% glycerin and its vehicle on skin barrier properties (2001)

Glycerol accelerates recovery of barrier function in vivo (1999)

Hydration of the stratum corneum (1986)