Licorice Root Extract for Pigmentation: Does It Actually Work?

You've seen it on ingredient lists for years — sometimes as "Glycyrrhiza Glabra Root Extract," sometimes just as "licorice extract." Indian skincare traditions have used mulethi (the Hindi name for licorice root) for centuries. Western dermatology has been studying it since the 1990s.

Despite all of this, most people have no idea what licorice root extract actually does in a brightening product — whether it works, how it works, or whether the clinical evidence behind it matches the marketing.

Here's the honest answer — including the impressive in vitro number that gets quoted everywhere and the important context that almost never accompanies it.

Quick Answer 

Does Licorice Root Extract Work for Pigmentation? Yes — licorice root extract has real, documented brightening activity, primarily through its active compound glabridin, which inhibits tyrosinase and reduces UV-induced pigmentation. In vitro research found glabridin has a skin-lightening effect 16 times greater than hydroquinone in isolated cell studies. A double-blind clinical study found a hydroquinone-free formula containing glabridin outperformed 4% hydroquinone cream in brightening L* measurements and pigmentation reduction. A separate study found 7% licorice comparable to 2% hydroquinone for melasma. Licorice root extract is a genuinely evidence-backed brightening active — particularly for UV-induced pigmentation — though it works best as part of a multi-active formulation rather than as a standalone treatment.

What Licorice Root Extract Actually Is

Licorice root — Glycyrrhiza glabra — is a perennial herb used in traditional medicine across South Asia, China, and the Middle East for thousands of years. In Indian skincare tradition, mulethi powder has long been used as a brightening and complexion-evening ingredient.

Modern dermatological research identified two specific compounds in licorice root that drive its brightening activity:

Glabridin — the primary active compound. A polyphenol with multiple mechanisms: tyrosinase inhibition, antioxidant activity, and anti-inflammatory properties. It's the compound responsible for most of licorice extract's pigmentation-reducing effect.

Liquiritin — a secondary active compound with a different and complementary mechanism. While glabridin inhibits melanin production, liquiritin works by dispersing and redistributing melanin that's already been produced — breaking it up rather than stopping it at the source. This dual-mechanism within a single plant extract is what makes licorice root unusual compared to most single-mechanism brightening ingredients.

Two additional polyphenols — glabrene and isoliquiritigenin — also contribute to tyrosinase inhibition, with research showing the full extract's inhibitory effect on tyrosinase activity was greater than expected based on its glabridin content alone. This suggests the whole extract performs better than isolated glabridin, which has formulation implications.

The "16 Times Stronger Than Hydroquinone" Claim — What It Actually Means

This is the number that appears in almost every licorice root article, and it needs honest context because it's both impressive and frequently misrepresented.

Glabridin has been shown in vitro to have a skin-lightening effect 16 times greater than that of hydroquinone and might reduce UVB pigmentation.

The critical qualifier is in vitro — meaning in isolated cell studies, not on actual skin. In vitro potency doesn't translate directly to clinical results because:

• Skin is a barrier. How well a compound penetrates to reach melanocytes in living skin is a separate variable from how well it works once it gets there.
• Glabridin has stability challenges in formulations — it can degrade before reaching the skin if not properly stabilised.
• Concentration in a finished product, penetration enhancers, and formulation pH all affect real-world performance in ways in vitro testing doesn't capture.

The honest position: "16 times stronger than hydroquinone" is a real in vitro finding — not fabricated — but it describes isolated cell behaviour, not what you should expect from a licorice extract cream on your face. The clinical human trials are a more accurate picture of what actually happens on skin.

What Clinical Studies Found

Hydroquinone-Free Formula With Glabridin vs 4% Hydroquinone

In a single-centre, double-blind clinical study of 18 subjects comparing the efficacy of a hydroquinone-free formula containing glabridin against 4% hydroquinone cream in reducing UV-induced hyperpigmentation, the skin brightener demonstrated significant reductions in pigmentation compared to baseline and produced greater increases in L* brightness compared to hydroquinone.

This is the clinical finding that actually matters for practical use — a glabridin-containing formula outperforming 4% hydroquinone in measured brightening outcomes in a controlled human study. The formula was multi-ingredient (targeting different pathways in melanogenesis), not isolated glabridin alone, which reflects how the ingredient is most effectively used.

7% Licorice vs 2% Hydroquinone for Melasma

In a single-blinded study comparing the efficacy of belides, embilica, and licorice 7% to 2% hydroquinone in the treatment of melasma, the degree of depigmentation in both groups was not statistically different.

Matching 2% hydroquinone for melasma in a clinical comparison is a meaningful result — 2% hydroquinone is the standard OTC concentration prescribed for pigmentation management. Licorice extract at 7% performing equivalently without hydroquinone's side effect profile is the kind of finding that positions it as a genuinely viable alternative.

Combination With Tranexamic Acid and Niacinamide

A clinical assessment of a multimodal combination of tranexamic acid, niacinamide, and licorice root extract found statistically significant improvement in pigment intensity, spot size, pigment extent, pigment homogeneity, brightness, clarity, and overall skin dyspigmentation at week 16 — with no skin tolerability issues identified.

This finding directly supports what the in vitro research predicted — licorice root extract performs best in combination with complementary actives, not as a standalone treatment.

The Three Mechanisms Working at Once

This is what separates licorice root extract from most single-mechanism brightening actives:

Mechanism 1 — Tyrosinase inhibition (Glabridin + Glabrene + Isoliquiritigenin): Slows melanin production at the enzyme level — the same step targeted by Alpha Arbutin and TYROSTAT-09. Multiple compounds contribute to this, which is why the whole extract outperforms isolated glabridin.

Mechanism 2 — Melanin dispersion (Liquiritin): Breaks up and redistributes melanin that's already been produced and transferred to surface skin cells. This is a mechanism almost no other common brightening ingredient shares — and it directly targets existing visible pigmentation, not just future production.

Mechanism 3 — Anti-inflammatory and antioxidant (Glabridin as ROS scavenger): Glabridin selectively inhibits tyrosinase activity without causing skin irritation and also exhibits anti-inflammatory and photoprotective effects. Reducing inflammation is directly relevant for Indian skin, where almost every pigmentation concern has an inflammatory component that keeps re-triggering melanin production.

Licorice Root vs Other Brightening Actives

The Honest Assessment — What It Can and Can't Do

What licorice root extract genuinely does well:

• Inhibits tyrosinase through multiple compounds simultaneously
• Disperses existing melanin at the surface — an action most other brightening actives don't have
• Anti-inflammatory support that's relevant for ongoing PIH triggers
• Very low irritation risk — validated across skin types including darker tones
• Works synergistically with other actives, particularly niacinamide and tranexamic acid

Where the evidence is thinner:

• Most of the strongest in vitro data (the "16x" finding) doesn't directly translate to guaranteed clinical performance
• Fewer large-scale RCTs than Alpha Arbutin or established tyrosinase inhibitors
• Glabridin has formulation stability challenges — not all licorice extract products deliver active concentrations to the skin
• Effective concentration in OTC products isn't always disclosed, making it difficult to assess dose

Bottom line: Licorice root extract works — but the evidence is strongest in multi-active formulations where it complements rather than replaces dedicated tyrosinase inhibitors.

How to Use Licorice Root Extract Effectively

In a routine: Licorice root extract works well alongside Alpha Arbutin, Niacinamide, and stable Vitamin C. Its melanin-dispersing action via liquiritin fills a gap that tyrosinase inhibitors alone leave — treating existing visible pigmentation at the surface while upstream inhibitors slow new production.

In a product: Look for "Glycyrrhiza Glabra Root Extract" on the label — ideally disclosed in the first half of the ingredient list, which suggests a meaningful concentration. Products listing it near the end may contain only trace amounts insufficient to produce clinical results.

With SPF: Like every brightening active, licorice extract's effect is significantly enhanced by daily SPF 50+. UV exposure is the primary trigger it's been most studied against — skipping SPF continuously reactivates the pathway it's trying to slow.

Myth vs Fact

Myth: Licorice root extract is "16 times stronger than hydroquinone" in skincare products. Fact: This is an in vitro finding from isolated cell studies — not a clinical result from skin application. Real-world performance depends on formulation stability, skin penetration, and concentration. Clinical human studies show licorice extract performing comparably to low-concentration hydroquinone (2%) — meaningful, but not 16x superior in practice.

Myth: Natural ingredients like licorice can't be as effective as synthetic actives. Fact: Glabridin's in vitro tyrosinase inhibition data is backed by clinical studies showing it outperforms 4% hydroquinone in at least one double-blind comparison. "Natural" vs "synthetic" is not a useful predictor of efficacy — the mechanism and the clinical evidence are.

Myth: If a product contains licorice extract, it will lighten skin. Fact: The concentration matters. Glabridin has stability challenges in formulations, and many products list licorice extract as a label-friendly ingredient without delivering meaningful amounts to the skin. Products disclosing concentration and using stabilised extracts are more likely to deliver clinical benefit.

Quick Tips

• Look for it in the first half of the ingredient list — this suggests concentration is high enough to be meaningful rather than token
• Pair with Niacinamide — the combination of licorice's melanin-dispersing action (liquiritin) with Niacinamide's melanin transfer inhibition covers more of the pigmentation pathway together
• Use with SPF 50+ — licorice extract's photoprotective benefits support but don't replace daily sun protection
• Don't expect it to be a standalone solution — even the strongest clinical evidence for licorice extract uses it in multi-active formulations, not alone