A Phase 4 interventional study of Tranexamic Acid (TXA) and melatonin (Circadin) in Melasma, Treatment Outcome and Recurrence, sponsored by Thammasat University. Active, not recruiting at 1 site in Thailand. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-06-24.
Sponsored by Thammasat University · Phase 4, Interventional, and Treatment
This study compares the effectiveness of two oral medications-melatonin and tranexamic acid -in treating melasma, a common skin condition that causes dark facial patches.
Participants will be randomly assigned to receive either melatonin, tranexamic acid, or a placebo once daily at bedtime for 12 weeks. During this treatment phase, all participants will also apply a broad-spectrum sunscreen and a base cream.
After 12 weeks, participants will stop the oral medication but continue using the sunscreen and base cream for an additional 12 weeks to assess recurrence of melasma.
The study evaluates improvement in skin pigmentation, recurrence after treatment cessation, quality of life, and patient satisfaction.
This clinical trial will be conducted at Benchakitti Park Hospital, Bangkok, Thailand, and will enroll 75 adult participants.
Melasma is a chronic skin disorder characterized by symmetrical, hyperpigmented patches on sun-exposed areas, especially the face. Although its exact cause is not fully understood, hormonal influences, ultraviolet (UV) exposure, and genetic predisposition are contributing factors.
Tranexamic acid (TXA), an antifibrinolytic agent, has shown promising results in treating melasma by inhibiting melanogenesis through the plasminogen-plasmin pathway. Melatonin (MLT), a hormone with antioxidant and anti-inflammatory properties, has also demonstrated potential benefits in melasma management by reducing oxidative stress and interfering with the melanin synthesis pathway.
This prospective, randomized, controlled, evaluator-blinded clinical trial aims to compare the efficacy and recurrence outcomes of oral TXA (500 mg), oral MLT (2 mg), and placebo, each administered once daily for 12 weeks. After discontinuing the oral treatment, all participants will continue using sunscreen and base cream for an additional 12 weeks to evaluate recurrence.
Outcome measures include modified Melasma Area and Severity Index (mMASI), Mexameter-based pigmentation indices, quality of life scores (DLQI), and patient satisfaction (VAS). The study is conducted at Benchakitti Park Hospital and includes 75 adult participants with epidermal or mixed-type melasma.
170 studies on the registry are indexed under Melanosis; 46 are open to participants now.
This study's enrollment of 75 is above the median of 40 across 157 interventional studies indexed under Melanosis.
Browse Melanosis studies →Thammasat University is the lead sponsor of 85 studies on the registry; 16 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive 500 mg of oral tranexamic acid (Transamin®) once daily at bedtime for 12 weeks, along with a broad-spectrum sunscreen and a base cream.
Drug: Tranexamic Acid (TXA)
Participants will receive 2 mg of oral melatonin (Circadin®) once daily at bedtime for 12 weeks, along with a broad-spectrum sunscreen and a base cream.
Drug: melatonin (Circadin)
Participants will receive a placebo capsule once daily at bedtime for 12 weeks, along with a broad-spectrum sunscreen and a base cream.
Drug: Placebo
500 mg oral tranexamic acid (Transamin®), taken once daily at bedtime for 12 weeks.
2 mg oral melatonin (Circadin®), taken once daily at bedtime for 12 weeks.
Placebo capsule identical in appearance, taken once daily at bedtime for 12 weeks.
Change in modified Melasma Area and Severity Index (mMASI)
Change in modified Melasma Area and Severity Index (mMASI) score from baseline to Week 12. The mMASI ranges from 0 to 14.4, with higher scores indicating more severe melasma.
Time frame: Baseline, Week 4, Week 8, Week 12
Change in modified Melasma Area and Severity Index (mMASI) (Recurrence)
Recurrence is defined as an increase in mMASI score ≥50% from Week 12 to Week 24. The mMASI ranges from 0 to 14.4; higher scores indicate worse melasma.
Time frame: Week 12, Week 16, Week 20, Week 24
Melanin and Erythema Index
Change in Melanin Index and Erythema Index at baseline to 24 weeks, measured by Mexameter. Higher values indicate increased pigmentation and erythema, respectively
Time frame: Baseline, Week 4, Week 8, Week 12, Week 16, Week 20, Week 24
Change in skin texture, pore size, fine line (Antera 3D imaging)
Quantitative skin analysis using Antera 3D® imaging at baseline to 24 weeks. Lower scores indicate smoother texture, smaller pores, and fewer fine lines.
Time frame: Baseline, Week 4, Week 8, Week 12, Week 16, Week 20, Week 24
Dermatology Life Quality Index (DLQI) score
Change in Dermatology Life Quality Index (DLQI) from baseline to 24 weeks. DLQI ranges from 0 to 30. Higher scores indicate greater impairment in quality of life.
Time frame: Baseline, Week 12, Week 24
Patient satisfaction (Visual Analog Scale)
Patient satisfaction score at every 4 weeks using Visual Analog Scale (VAS) from 0 to 10. Higher scores indicate greater satisfaction.
Time frame: Baseline, Week 4, Week 8, Week 12, Week 16, Week 20, Week 24
Adverse events (AEs)
Number and severity of treatment-emergent adverse events during the 12-week intervention
Time frame: Week 4, Week 8, Week 12
Plan to share: No — Individual participant data (IPD) will not be shared due to confidentiality concerns and lack of a formal data-sharing infrastructure. Data will be available upon reasonable request in de-identified, summary form only
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This study is active, not recruiting, as verified in Jun 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Melatonin
Thammasat University