Introduction: Using fluoxetine is one of many weight loss strategies. A serotonin reuptake inhibitor indicated for depression believed to impact weight control by changing an individual's appetite; however, its benefit-risk ratio is unclear. The aim of this review was to assess the efficacy and safety of fluoxetine in reducing weight in adults with overweight or obesity.
Methods: We searched Cochrane Library, MEDLINE, Embase, and other databases without language restrictions. Cochrane Collaboration tool and GRADE instrument assessed the risk of bias of randomized controlled trials and certainty of their evidence. We conducted random-effects meta-analyses and calculated the risk ratio/mean difference with 95% confidence intervals for the outcomes.
Results: We included 19 trials (2,216 adults) and found that fluoxetine may reduce weight by -2.7 kg (95% CI -4 to -1.4; p < 0.001) and body mass index by -1.1 kg/m2 (95% CI -3.7 to 1.4), compared with placebo; however, it would cause approximately twice as many adverse events, such as dizziness, drowsiness, fatigue, insomnia, or nausea.
Conclusions: Although low-certainty evidence suggests that off-label fluoxetine may reduce weight, high-certainty research is needed to be conducted in the future to determine its effects exclusively as well as whether it is useful when combined with other agents. This article is based on a Cochrane Review published in the Cochrane Database of Systematic Reviews 2019, Issue 10, DOI: 10.1002/14651858.CD011688.pub2. Cochrane Reviews are regularly updated as new evidence emerges, and in response to feedback, it should be consulted for the most recent version of the review.
Keywords: Adverse events; Fluoxetine; Obesity; Weight loss.
© 2022 The Author(s). Published by S. Karger AG, Basel.