Effectiveness and Safety of Mud Therapy (Pelotherapy) for Musculoskeletal Disorders: A Systematic Review and...

Mud therapy (pelotherapy)-the therapeutic application of natural mineral-rich mud, peat, or clay-is practiced in at least 40 countries as a non-pharmacological adjunct for musculoskeletal disorders (MSDs). This systematic review synthesized evidence on the effectiveness and safety of pelotherapy in adults with MSDs. PubMed, CENTRAL, Embase, CINAHL, Scopus, LILACS, SCI, and SSCI were searched from inception to April 2026 without language restrictions. Randomized and controlled clinical trials comparing pelotherapy with sham, usual care, or no treatment in adults with confirmed MSDs were eligible. Two reviewers independently conducted screening, data extraction, and risk-of-bias assessment using Cochrane RoB 2. Random-effects meta-analyses calculated standardized mean differences (SMDs; Hedges' g) with 95% confidence intervals (CIs), and certainty was assessed using GRADE. The protocol was prospectively registered in PROSPERO. Thirty-three studies (n = 2,651) were included in the qualitative synthesis, and 28 randomized controlled trials (n = 2,186) contributed to meta-analysis. Pelotherapy significantly reduced pain post-intervention (SMD -0.74; 95% CI -0.91 to -0.57; I² = 62%; moderate certainty), with sustained effects at 3 months (SMD -0.61; 95% CI -0.81 to -0.41) and 6 months (SMD -0.49; 95% CI -0.71 to -0.27). Physical function also improved (SMD -0.69; 95% CI -0.87 to -0.51). Osteoarthritis demonstrated the largest effects, particularly knee OA (SMD -0.86). The most common adverse events were skin erythema (6.5%) and transient fatigue (4.8%), with no significant increase in serious adverse events (RR 0.98; 95% CI 0.61-1.58). Pelotherapy provides clinically meaningful and sustained reductions in pain and disability, with a generally favorable safety profile. Evidence is strongest for osteoarthritis, supporting its use as an adjunct in naturopathic and integrative medicine.