Licorice and Alpha Arbutin Serums for Winter Pigmentation

Dark marks do not take a winter break. Here is why they linger, what licorice and alpha arbutin have shown in studies, and how to use them without making things worse.

Why Dark Marks Linger

Many dark marks are post-inflammatory hyperpigmentation: the skin darkens after irritation, a breakout or a rash. It is a common aftermath of inflammatory skin problems, and it affects darker skin tones more often and more severely^[1]. Winter makes this more likely, because cold, dry air reduces barrier function and makes skin more reactive to irritants^[2]. Irritation leaves marks, and marks can take a long time to fade. The UV that darkens them does not take a winter holiday either, which is why we covered cold weather, same sun earlier this season.

The Targets: Tyrosinase and Inflammation

Melanin is made with the help of an enzyme called tyrosinase, so many lightening ingredients work by slowing it down. Reviews of treatment for post-inflammatory marks list arbutin and certain licorice extracts among the topical tyrosinase inhibitors that can lighten areas of excess pigment, alongside sunscreen as a first-line partner. The same review adds a warning: be careful with all treatments, because irritation can make the marks worse^[1]. Indian dermatologists reached a similar view in a 2026 consensus: combination approaches that target pigment production, inflammation and sun protection, with prevention emphasized for Fitzpatrick skin types III to VI^[3].

Licorice: What the Evidence Is

Glabridin is the main active in the oil-soluble part of licorice extract. In lab tests on mouse melanoma cells it inhibited tyrosinase, and in guinea pigs, 0.5% glabridin applied to the skin reduced UVB-induced pigmentation and redness^[4]. That is animal and cell evidence, from a cosmetics company (Kanebo). In people, a small split-face trial in 20 women with melasma compared a cream with liquiritin (a licorice-derived compound) against a vehicle cream twice daily for four weeks, and its title reports improvement^[5]. The abstract does not give the figures, so read it as an encouraging small study rather than a settled result.

Alpha Arbutin: What the Evidence Is

Alpha arbutin is a plant-derived compound that also slows tyrosinase. In a 2024 laboratory study, it reduced UVB-induced skin damage in a dose-dependent way, and was linked to the tyrosine pathway that makes melanin^[6]. One author's affiliation is a company research institute (HBN Research Institute). A broader review notes that its skin-lightening efficacy, alone and in combination, has been clinically evaluated. It adds two cautions: arbutin rarely causes dermatitis, and some products may generate hydroquinone during use, so caution is recommended^[7]. For how alpha arbutin works in more detail, see our Journal explainer.

Using Them Safely in Winter

• Treat the cause first. Calm irritation and dryness, because inflamed skin keeps making new marks. Our posts on sensitivity and the barrier cover this.
• Introduce one new active at a time, and patch test first, since irritation can worsen marks^[1].
• Use sunscreen every morning. Without it, marks darken again.
• Expect weeks to months. The trials here ran for four weeks or longer, and marks fade slowly.
• See a dermatologist for large, symmetrical patches on the cheeks or forehead, which may be melasma and needs a proper diagnosis. Our Journal piece on sun spots, acne marks and melasma explains the difference.