Efficacy of Varenicline in Smoking Cessation—A Systematic Review and Meta-analysis

Background: Tobacco use is a leading cause of morbidity and mortality. Smoking cessation significantly reduces related health risks. Varenicline, a partial nicotine receptor agonist, may aid cessation by reducing cigarette consumption and dependence. Objective: The study aimed to find out the efficacy of varenicline for smoking cessation through a systematic review and meta-analysis. Methods: The focused question was: “Is varenicline effective in smoking cessation compared to other replacement therapies?” Electronic databases, including PubMed, PubMed Central, Google Scholar, Cochrane, and the National Guideline Clearinghouse, were searched using keywords such as “varenicline,” “tobacco cessation,” and “pharmacotherapy.” Studies from 2008 to 2025 were screened. Only full-text, English-language randomized controlled trials (RCTs) were included for qualitative and quantitative assessment. A random-effects model was used to calculate odds ratios. Results: Fifteen studies met the inclusion criteria for the systematic review. Quality assessment using the Cochrane RoB 2 tool revealed that 12 studies had a low risk of bias, two had a moderate risk, and one had a high risk. Out of these, five RCTs were included in the meta-analysis. The pooled analysis revealed a statistically significant effect favoring varenicline for smoking cessation, with an overall odds ratio (OR) of 3.11. Conclusion: Many of the studies have shown good responses related to its efficacy, and varenicline is the better drug of choice for smoking cessation. Even though varenicline is effective for tobacco cessation, combination therapy increases the abstinence rate.