Licorice extract often appears in formulas for dark spots, and it is almost always described as a soothing ingredient. That’s only half the story: when it comes to discoloration, the interesting part of this root is a fat-soluble molecule called glabridin.
Licorice does two different jobs with two different fractions. Glabridin, which is fat-soluble, interferes with tyrosinase. Glycyrrhetinic acid, which is water-soluble, is the anti-inflammatory part. If an extract does not state what it is standardized for, there is no way to know which of the two you are buying.
Article written by Elisa Avalle, founder of LeLang Skin Care and dermocosmetics specialist. Cover image generated with the support of artificial intelligence.
[INDICE:h2]
What it is
It is obtained from the root of Glycyrrhiza glabra. On the INCI list, it appears as Glycyrrhiza Glabra Root Extract, or in purified forms as Dipotassium Glycyrrhizate, which is the salt of glycyrrhetinic acid and serves a completely different purpose.
Glabridin is an isoflavan present in very small quantities, concentrated in the root’s oily fraction. This has a practical consequence: an aqueous licorice extract, however good, contains little or none of it.
Why it matters for discoloration
Glabridin inhibits tyrosinase, the enzyme that initiates melanin production. Compared with other inhibitors, it has an advantage recognized in the literature: it does so without the cytotoxicity toward melanocytes characteristic of more aggressive molecules. It is an active ingredient that slows a process, rather than damaging a cell.
There is also a second reason, mentioned less often and perhaps more important. Many dark spots do not come from the sun but from previous inflammation: a pimple, waxing, sunburn, or a cosmetic treatment. In these cases, the root’s anti-inflammatory component works on the cause, while the tyrosinase inhibitor works on the effect. It is rare to find both in the same plant.
The limitation: standardization
Here is the honest truth. The amount of glabridin in an extract varies enormously depending on the root’s origin and the extraction method, and the label never lists it: the INCI names the plant and the part used, not how much active ingredient it contains.
This means that two products listing the same ingredient can behave very differently. You can only get this information from the manufacturer, and it is the same reason I am wary of ingredient rankings for plant extracts: the species tells you little; standardization tells you everything.
What to combine it with
The approach to treating dark spots is always the same: target multiple points in the chain. Licorice works well with kojic acid and alpha-arbutin, which work on the same enzyme through different pathways, and with niacinamide, which acts further downstream.
With melasma, which also has a vascular component, the approach is different. I discussed this in my article on tranexamic acid.
Cosmetic products do not treat any clinical condition and cannot claim to do so, under Regulation (EC) 1223/2009 and Regulation (EU) 655/2013. Spots that appear suddenly, change shape, color, or size, or widespread hyperpigmentation should be assessed by a doctor.
When to look for it
- For reactive skin, when stronger active ingredients are not tolerated: it is one of the gentler options in this category.
- For post-inflammatory spots, when it is important to address the inflammation that caused them.
- In combination formulas, not on its own: the effect is real but modest, and combining it with other mechanisms is the only way to make it noticeable.
- In fall and winter, when UV exposure decreases and a treatment can run its full eight to twelve weeks.
SPOT DEFENCE 50 SPF SPF 50 anti-dark-spot facial sunscreen serum With encapsulated vitamin C, plant glycogen and postbiotic ferments, for... Discover SPOT DEFENCE 50 SPF
If you are unsure what type of spot you have, LeLang partner pharmacists can take a look with you: everything else depends on the type.
Not sure where to start with dark spots?
Book a free virtual consultation: we’ll assess your skin together and create a personalized routine.
Frequently asked questions
What is glabridin?
Glabridin is an isoflavan present in very small quantities in the root of licorice, Glycyrrhiza glabra, and is concentrated in its oily fraction. It is the part of the plant that matters when it comes to dark spots because it interferes with tyrosinase, the enzyme that initiates melanin production. This is why an aqueous licorice extract contains little or none of it.
What is licorice used for in cosmetics?
It does two jobs using two different fractions. Glabridin, which is fat-soluble, slows melanin production by acting on tyrosinase, without the cytotoxicity toward melanocytes typical of more aggressive molecules. Glycyrrhetinic acid, which is water-soluble, has an anti-inflammatory effect. On the label, its salt appears as Dipotassium Glycyrrhizate; do not confuse it with glabridin.
Why is licorice recommended for spots left by pimples?
Because many spots result from previous inflammation, such as a pimple, waxing, or sunburn. In these cases, the root’s anti-inflammatory component addresses the cause of the spot, while glabridin works on pigment production. It is rare to find both actions in the same plant, which is what makes licorice interesting for post-inflammatory discoloration.
How can you tell how much glabridin a product contains?
You cannot tell from the label: the INCI lists the plant and the part used, not the amount of active ingredient. Glabridin content varies significantly depending on the root’s origin and the extraction method, so two products listing the same ingredient can behave differently. Only the manufacturer can provide information about its concentration.
Is licorice suitable for sensitive skin?
Yes, it is one of the gentler options for people with dark spots and reactive skin that cannot tolerate stronger active ingredients. Its effect on pigmentation is real but modest, so it works best in formulas combined with kojic acid, alpha-arbutin, or niacinamide. Fall and winter are ideal, with daily sun protection and a treatment lasting eight to twelve weeks.
Sources for this article
- Review literature on plant-based tyrosinase inhibitors: glabridin, enzyme activity, and cytotoxicity profile.
- Rivas S., Pandya A.G. (2013). "Treatment of melasma with topical agents, peels and lasers: an evidence-based review". American Journal of Clinical Dermatology, vol. 14, no. 5, pp. 359-376.
- Regulation (EC) No. 1223/2009 of the European Parliament and of the Council on cosmetic products.
- Commission Regulation (EU) No. 655/2013, common criteria for the justification of claims used in relation to cosmetic products.
On the website: Arbutin · Kojic acid · Skin discoloration
