Dr. Andrew Alexis Highlights 2-MNG as Option to Treat Acne-Related PIH
The topical agent 2-Mercaptonicotinoyl glycine (2-MNG), also marketed as Melasyl, could be key to treating acne-related postinflammatory hyperpigmentation (PIH) in skin of color, Andrew Alexis, MD, MPH, said at the Skin of Color Update in New York, New York.
Dr. Alexis presented on managing acne in patients with skin of color, with a particular focus on strategies to address PIH in Fitzpatrick skin types IV to VI, and he emphasized emerging topical ingredients, treatment layering, and the importance of integrating PIH-directed therapies into acne regimens from the outset.
Unlike many pigment-correcting agents that act by inhibiting tyrosinase, Dr. Alexis said, 2-MNG targets an earlier stage of melanogenesis. It conjugates with melanin precursors, thereby disrupting the synthesis of both melanin and pheomelanin. This novel mechanism may offer advantages in reducing the development of new pigment following inflammation.
Dr. Alexis cited a small, recently published clinical trial in which a 2-MNG–containing formulation was tested in patients with skin types IV to VI and acne-related PIH.1 After approximately 12 weeks of treatment, patients showed statistically significant improvements from baseline. Although the study was limited in size, the clinical improvement was notable and supports the use of 2-MNG as part of a multimodal regimen.
In clinical practice, Dr. Alexis recommended using pigment-targeting cosmeceuticals such as 2-MNG in the morning and retinoid-based formulations in the evening. This stepwise layering approach addresses both active acne lesions and PIH simultaneously, improving tolerability and outcomes in patients with skin of color.
“We could take a prescription agent such as a triple-combination retinoid/benzoyl peroxide/clindamycin, or another retinoid-containing formulation, at night and maybe add in the morning a cosmeceutical like this one to help further reduce the hyperpigmentation,” Dr. Alexis said, “or maybe use topical azelaic acid in the morning coupled with a retinoid-containing product at night.”
Dr. Alexis also highlighted the importance of selecting skincare that supports treatment tolerability, particularly in skin of color, where irritation can exacerbate pigmentary changes. Non-comedogenic moisturizers, barrier repair agents, and gentle cleansers form the foundation of a well-structured regimen, he said.
1. Demessant-Flavigny AL, Petkar G, Jodun D, Le Dantec G, Le Floc'h C, Kerob D. Efficacy of a 2-MNG-Containing Depigmenting Serum in the Treatment of Post-Inflammatory Hyperpigmentation. J Cosmet Dermatol. 2025;24(2):e16735. doi: 10.1111/jocd.16735. Epub 2024 Dec 26.