This meta-analysis of 37 randomized controlled trials involving 2,292 participants found that L-carnitine supplementation produces a modest reduction in body weight, BMI, and fat mass, particularly in adults who are overweight or obese. Weight decreased by approximately 1.21 kg and fat mass by 2.08 kg, while no significant effects were observed on waist circumference or body-fat percentage. A dose-response analysis suggested that 2,000 mg/day may provide the greatest effect on weight reduction.