Objective: This meta-analysis of randomized controlled trials (RCTs) on the Transcendental Meditation® (TM) technique updates previous meta-analyses and examines the influence of baseline anxiety, age, practice duration, regularity, study quality, authors' affiliation, and type of control group on effect sizes.

Design: Systematic literature review using Comprehensive Meta-Analysis (CMA) software for main effect size analysis, bias analysis, meta-regression, and moderators. The search included meditation-specific databases.

Results: Over 600 scientific works on TM were found; 14 specifically addressed trait anxiety covering 16 studies with 1,295 participants. No adverse effects were reported. The standardized mean difference, d, for TM vs. active alternatives (10 studies) was d=-0.50 (95% CI, -0.70 to -0.30; p=0.0000005). Compared to usual care control (16 studies), d=-0.62 (95% CI, -0.82 to -0.43; p=1.37E-10). Meta-regression showed baseline anxiety predicts the reduction in anxiety (p=0.00001). High baseline anxiety population (80–100 percentile) showed larger effects (-0.74 to -1.20), reduction to 53–62 percentile. Repeated measures studies showed significant reduction after 2 weeks and stable effect at 3 years.

Conclusion: TM practice is more effective than usual care and most alternative treatments, with the greatest effects in people with high anxiety. Further medically supervised research is recommended.