Melatonin Supplementation in the Management of Irritable Bowel Syndrome: An Updated Systematic Review and Meta-Analysis
In brief
Melatonin nearly halves moderate-to-severe IBS symptoms in pooled trials
Across seven trials involving 391 adults, melatonin was linked to a 48% lower likelihood of moderate-to-severe IBS symptoms than placebo, with improvements in pain frequency and bowel movement frequency. Quality of life and sleep did not significantly improve, and the evidence is based on small trials; larger studies are needed to confirm longer-term benefit and safety.
- Journal
- Journal of gastroenterology and hepatology (Q1)
- Published
- 22 September 2026
- Study design
- Systematic review / meta-analysis of RCTs
- Evidence level
- Level 1, High (CEBM 1a)
- Authors
- Ghadeer Ahmad Mahdi, Noor Abotaiban, Ahmed Farid Gadelmawla, Mohammed Alfartaj, Saud M Almutairi, Faisal E Alenezi, et al.
- PMID
- 42770627
- DOI
- 10.1111/jgh.70743
Why clinicians should know about it
- Picked for Gastroenterology (top studies of the week, 27 September 2026): Melatonin supplementation improves IBS outcomes (meta‑analysis)
- Picked for Gastrointestinal and Colorectal Surgery (top studies of the week, 27 September 2026): Melatonin for IBS systematic review
Abstract
BACKGROUND: Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction characterized by recurrent abdominal pain and altered bowel habits, with substantial effects on quality of life and healthcare utilization. Melatonin has been proposed as a potential adjunctive therapy because of its effects on visceral sensitivity, gastrointestinal motility, and gut-brain signaling. We conducted an updated systematic review and meta-analysis of randomized placebo-controlled trials evaluating melatonin supplementation in adults with IBS. METHODS: PubMed, Web of Science, Cochrane CENTRAL, Scopus, and Embase were searched from inception to April 13, 2026. Randomized, double-blind, placebo-controlled trials evaluating oral or sublingual melatonin in adults with IBS were included. Parallel-group trials were quantitatively synthesized, while crossover trials were narratively summarized when outcome reporting was unsuitable for pooling. Risk of bias was assessed using RoB 2. RESULTS: Seven randomized trials involving 391 participants were included; four contributed to quantitative synthesis and three were narratively reviewed. Melatonin significantly reduced moderate-to-severe IBS symptoms versus placebo (RR = 0.52, 95% CI = 0.39-0.71, p < 0.0001), improved pain frequency (SMD = 0.59, 95% CI = 0.27-0.92, p = 0.0003) and improved frequency of defecation (SMD = 0.42, 95% CI = 0.12-0.72, p = 0.0056). No significant differences were observed for overall quality of life or global sleep quality. Abdominal distension and abdominal pain intensity numerically favored melatonin without reaching statistical significance. Reported adverse effects were mild and infrequent. CONCLUSION: Melatonin may improve overall IBS symptom severity, pain-related outcomes, and bowel habit measures, with an acceptable short-term safety profile. Larger, high-quality trials are needed to confirm long-term efficacy.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.