Combined micro-needling with topical metformin versus micro-needling with topical placebo in the treatment of melasma - concurrent split-face study

Oct 10, 2026

Melasma is an acquired disorder of melanogenesis that is difficult to treat and commonly recurs after therapy. The study evaluates whether topical metformin, when combined with micro-needling, can provide stronger therapeutic benefit than micro-needling with topical placebo. Eighteen patients received split-face treatment for four sessions at 2-week intervals: micro-needling plus metformin on one side and micro-needling plus placebo on the other. Hemi-mMASI scores showed a significant reduction on the metformin combination side versus placebo (2.39 ± 1.42 vs 4.72 ± 1.27, p = 0.001). The combined therapy improved effectiveness without apparent side effects.

LanguageEnglish

CategoryHealthcare

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Pages7

Reading Time18 min

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Abstract

Introduction

Patients and Methods

Archives of Dermatological Research (2025) 317:13 [https://doi.org/10.1007/s00403-024-03449-4](https://doi.org/10.1007/s00403-024-03449-4) Combined micro‑needling with topical metformin versus micro‑needling with topical placebo in the treatment of melasma: a concurrent split‑face study Hagar Bessar1 · N. Arebi2 · M. El‑Sayed1 · B. Elkholy1 Received: 10 August 2024 / Revised: 11 September 2024 / Accepted: 8 October 2024 © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024 Abstract Melasma is an acquired dysfunction of melanogenesis, that poses a major therapeutic challenge and tends to recur after therapy. Several combination therapies are being tested nowadays for the treatment of melasma, with promising results. Metformin, an anti-diabetic medication, seems to inhibit melanogenesis by different mechanisms. In addition, there has been a long-term improvement in melasma after microneedle therapy. To evaluate the potential therapeutic role of topical metformin combined with micro-needling for the treatment of melasma. Eighteen patients with melasma received treatment in split-face manner, right side with micro-needling and topical metformin, while the left side was treated with micro-needling and topical placebo for four sessions at 2-week intervals. Hemi-mMASI score was used for the final evaluation of results. The variability pattern in Hemi-mMASI score between both sides revealed significant reduction in the right side (microneedling + metformin), as compared to the left side (micro-needling + placebo) (2.39 ± 1.42 vs 4.72 ± 1.27, p = 0.001) . The effectiveness of topical metformin in the management of melasma could be significantly improved by pretreatment with micro-needling as a combined therapy, without any apparent side effects. Keywords Melasma · Micro-needling · Metformin Introduction Melasma is an acquired dysfunction of melanogenesis appears as symmetrical hyperpigmentation in the sunexposed areas ranging from lightly brown to more dark patches on forehead, malar areas, nose, and even on the chin. The pathogenesis is not obvious, but some triggers were identified such as exposure to ultraviolet light, pregnancy, oral contraceptives, hormone replacement therapy, inflammation, cosmetic products, darker complexions, steroids and photosensitizing medicines and family history [1] . These factors lead to initiation of different signaling pathways, such as melanocyte-stimulating hormone (MSH) * Hagar Bessar[dr_hagarawadbessar@yahoo.com](dr_hagarawadbessar@yahoo.com) 1 Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Zagazig University, Zagazig, Sharkia, Egypt 2 Department of Dermatology and Venereology, Gharyan University, Gharyan, Libya, Egypt which indirectly stimulates tyrosinase and microphthalmiaassociated transcription factor (MITF) by cyclic adenosine monophosphate (MSH/cAMP), the tyrosine kinase receptor (KIT) and the Wnt-signaling pathway, which in its turn activate melanogenesis and result in melasma development [2] . The dermatologists' challenges in the management of melasma were always due to its recurrent nature. Different treatment methods to reduce melanin synthesis were tested, but none of them are very efficient to produce long-term remission [3] . For decades, hydroquinone had been the gold standard for managing hyperpigmentation. It modifies melanosome production, and boosts melanosome disintegration. Unfortunately, long-term applications of hydroquinone may result in significant adverse effects [4] . Other options, as triplecombination cream (TCC) of hydroquinone, tretinoin, and steroid, tranexamic acid, azelaic acid, kojic acid, arbutin, chemical peeling, lasers, ascorbic acid, rucinol, oligopeptides, silymarin, and various extracts, have been used with varying success. Therefore, the search for ideal treatment offering both effective and safe hypopigmentation in melasma, without long-term

FAQs

How was the split-face treatment designed in this study?

Eighteen patients were treated with four sessions at 2-week intervals. The right side received micro-needling plus topical metformin, while the left side received micro-needling plus topical placebo.

Which outcome measure was used to evaluate treatment results?

Results were assessed using the Hemi-mMASI score for both sides and comparing score variability between treatments.

What did the study find about topical metformin combined with micro-needling?

The right side (micro-needling + metformin) showed a significant reduction in Hemi-mMASI score compared with the left side (micro-needling + placebo), with no apparent side effects reported.

Oct 10, 2026

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