Using metformin to treat melasma in Latin American women

Oral Metformin in the Treatment of Melasma: a Prospective Trial in Latin American Women

Phase1; Phase2 Interventional University of Puerto Rico · NCT06845540

This study is testing if the diabetes drug metformin can help reduce dark patches on the skin caused by melasma in Latin American women.

Quick facts

PhasePhase1; Phase2
Study typeInterventional
Enrollment30 (estimated)
Ages21 Years and up
SexFemale
SponsorUniversity of Puerto Rico Academic / other
Locations1 site (San Juan, PR)
Trial IDNCT06845540 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the effectiveness of metformin in reducing melasma in Latin American women. Participants will take either 500 mg or 1000 mg of metformin daily for three months. The study involves two clinic visits, one at the start and one at the end, along with follow-up phone calls to monitor progress and side effects. The primary focus is to determine if metformin can improve the appearance of dark patches associated with melasma.

Who should consider this trial

Good fit: Ideal candidates are Latin American women aged 21 years or older with a diagnosis of epidermal or mixed melasma.

Not a fit: Patients who are pregnant, breastfeeding, or have a history of renal or liver disease will not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new option for women suffering from melasma, potentially improving their skin appearance and quality of life.

How similar studies have performed: While the use of metformin for melasma is a novel approach, other studies have explored its effects on skin conditions, but this specific application remains largely untested.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria: Latin American women aged 21 years or older, diagnosed epidermal or mixed melasma

Exclusion Criteria: pregnancy, breastfeeding, use of hydroquinone or tretinoin within 2 months before the study, or undergoing laser treatment, peels, microdermabrasion, or microneedling within 2 months of the study. Patients with a history of renal or liver disease, metformin allergy, diabetes, hypoglycemia, or those on medications that could interact with metformin will also be excluded.

Where this trial is running

San Juan, PR

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Melasmamelasmametformin
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.