BACKGROUND: Binge eating (BE) involves consuming unusually large amounts of food within a short period and feeling a loss of control. Neurobiological mechanisms underlying BE involve dysregulation of reward and inhibitory control systems, with the endogenous opioid system playing a key role. Opioid antagonists and the combination therapies with bupropion may have potential to reduce BE by affecting the reward system, but evidence regarding their effectiveness remains inconclusive. This meta-analysis reviewed randomized controlled trials (RCTs) exploring the effects of opioid antagonists on BE frequency, BE severity, body weight, and mood. METHODS: We systematically searched PubMed, Embase, Cochrane CENTRAL, Web of Science, and ClinicalTrials.gov to identify RCTs published before May 14, 2023,. The primary outcomes were BE severity and frequency. The secondary outcomes were percentage change in body weight and depressive symptoms. RESULTS: Eight RCTs were included in our analysis. Opioid antagonists significantly reduced BE frequency (standard difference in means [SMD] = -0.624, 95 % confidence interval [CI] = -1.181 to -0.067, p = 0.028) and changes in body weight percentage (SMD = -0.981, 95 % CI = -1.657 to -0.305, p = 0.004), with a moderate-to-large effect size. Conversely, opioid antagonists didn't significantly improve BE severity (Hedges' g = -0.210, 95 % CI = -0.431 to 0.011, p = 0.063) or depressive symptoms (Hedges' g = -0.190, 95 % CI = -0.434 to 0.053, p = 0.125). Meta-regression analysis revealed that the dosage of naltrexone served as a moderator in reducing BE frequency and body weight percentage. CONCLUSION: The present meta-analysis indicated that opioid antagonists effectively alleviate BE frequency and reduce percentage loss in body weight.