Glycyrrhetinic Acid: Are there side effects to its topical use?

Also known as enoxolone, glycyrrhetinic acid is an active ingredient found in the smooth licorice or Glycyrrhiza glabra. Known for its aromatic roots and its therapeutic properties, it has long been used in traditional medicine, particularly to soothe colds, coughs, and indigestions. It was often consumed in the form of an infusion or chewable paste in ancient times. Today, enoxolone is primarily recognized for its cosmetic virtues and the benefits it brings to the skin.

• Anti-inflammatory : Glycyrrhetinic acid operates on several levels to alleviate inflammation. It notably inhibits the activity of TNF-α and interleukin-1α, which are pro-inflammatory cytokines. This active ingredient can therefore be used to soothe itching or certain redness.

• Antibacterial : Glycyrrhetinic acid has been shown to have a bactericidal effect against certain resistant strains of Staphylococcus aureus. This molecule can therefore be useful in controlling bacterial populations living on the skin.

• Brightening : this property of glycyrrhetinic acid is debated, but it appears to inhibit tyrosinase, the key enzyme in the melanogenesis process. Therefore, this active ingredient could potentially help to reduce brown spots.

• Antioxidant : By stimulating the activity of certain antioxidant enzymes, glycyrrhetinic acid protects DNA, proteins, and cells from free radicals, which are responsible for premature aging, as well as pigmentation disorders and melanomas.

• Prevents skin aging : Glycyrrhetinic acid has been shown to inhibit the activity of collagenase, an enzyme that breaks down the peptide bonds of collagen, thereby degrading it. This active ingredient thus protects a protein essential to skin elasticity and delays the onset of wrinkles.

No side effects have been reported to date following the topical application of enoxolone. This active ingredient is gentle and non-irritating, and its concentration in cosmetic products is not subject to restriction by European cosmetic regulations. These regulations are based on Regulation (EC) No 1223/2009, which establishes the standards and requirements that these products must meet in order to protect consumer health.

Although it is not subject to a concentration limit, enoxolone is typically incorporated at rates between 0.05 and 2% in cosmetic care products. Indeed, this concentration range is sufficient to induce skin benefits. It's also worth noting that this molecule is not among the cosmetic actives advised against during pregnancy or breastfeeding. In fact, glycyrrhetinic acid can be considered suitable for the whole family as it can also be used by children over 3 years old.

• KALINOWSKA-LIS U. & al. 18β-Glycyrrhetinic acid: its core biological properties and dermatological applications. International Journal of Cosmetic Science (2019).

• Thèse de Mathilde BOURIQUAT. La réglisse : principales propriétés et utilisations (2020).