Research

Mixed

Orlistat combined with behavioral intervention results in greater weight loss (average 3.0 kg or 6.6 lb more) than placebo plus behavioral intervention at 12 months, though with higher rates of gastrointestinal adverse effects leading to withdrawal.

Orlistat (120 mg, 3x/day) combined with behavioral counseling helps you lose about 3 kg (6.6 lbs) more than placebo over 12 months. However, be aware that gastrointestinal side effects are common and lead to higher dropout rates. Serious side effects are not increased, but the modest benefit may not be worth the side effects for everyone.

ModerateSupportsLOW confidence
In the 12 trials that could be combined by meta-analysis, participants randomly assigned to orlistat lost 3.0 kg (6.6 lb) more (95% CI, -3.9 to -2.0 kg) than those receiving placebo after 12 months... Participants randomly assigned to receive orlistat were more likely to experience adverse effects and withdraw from trials because of adverse effects than those assigned to placebo.
Erin S. LeBlanc et al. · Annals of Internal Medicine · 2011

Why this rating

Based on 12 trials, but limited by high attrition, lack of post-discontinuation data, and only one good-quality trial.

Source

Effectiveness of Primary Care–Relevant Treatments for Obesity in Adults: A Systematic Evidence Review for the U.S. Preventive Services Task Force

Erin S. LeBlanc et al. · Annals of Internal Medicine · 2011

DOI 10.7326/0003-4819-155-7-201110040-00006

Meta-analysis · 58 studiesCited 403×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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