Network meta-analysis ranks tirzepatide 15 mg first, liraglutide 3.0 mg last for weight loss
A review of 24 trials ranks tirzepatide 15 mg first and liraglutide 3.0 mg last for weight loss, with tolerability differences that could affect who stays on treatment.
A network meta-analysis of 24 randomized trials ranked tirzepatide 15 mg highest and liraglutide 3.0 mg lowest among three GLP-1-based obesity drugs for weight loss [1]. The same analysis found that liraglutide 3.0 mg carried higher risks of any adverse event and of discontinuing treatment because of an adverse event [1].
The review was published in the Journal of Endocrinological Investigation [1]. It pooled phase 3 randomized controlled trials in adults aged 18 and older with a body mass index of at least 25 kg/m² [1]. All trials lasted at least 52 weeks and compared liraglutide, semaglutide or tirzepatide at approved weight-management doses against placebo or against each other [1]. Of the 24 trials included, 23 were eligible for the network meta-analysis [1]. The authors used random-effects models and ranked treatments with P-scores, a statistical method for ordering treatments across a network of comparisons [1]. The review is registered with PROSPERO under the number CRD420251014401 [1].
All of the drugs reduced body weight, waist circumference and BMI compared with placebo [1]. Tirzepatide 15 mg ranked highest for both weight and waist reduction across the analyses based on P-scores [1]. Liraglutide 3.0 mg produced the smallest weight loss [1].
The analysis also examined semaglutide at two doses. Semaglutide 7.2 mg ranked above semaglutide 2.4 mg on every efficacy measure, but the significant advantage in percentage of body weight changed appeared only in the subgroup of patients with diabetes [1]. The authors described the average added benefit of the higher dose as roughly 2 to 3 percentage points, calling it modest, and said it should be weighed against limited statistically significant differences between the doses, tolerability and patient preferences [1].
On safety, the review found no significant differences between treatments for serious adverse events [1]. Tirzepatide was associated with a higher risk of injection site reactions, while liraglutide was associated with higher risks of any adverse events and of discontinuation due to adverse events [1].
The abstract does not report specific average weight-loss percentages for each drug, so the size of the gap between them in percentage points or pounds has not been disclosed [1]. The authors reported considerable heterogeneity across trials for the efficacy outcomes, while finding limited evidence of inconsistency across the network [1]. Safety networks showed low to moderate heterogeneity [1].
Why it matters for patients
Rankings from a network meta-analysis describe average results across groups of trial participants. They do not predict how any one person will respond to a particular drug [1]. The authors frame the choice as a balance among efficacy, tolerability and patient preferences, and they note that differences between the two semaglutide doses were not statistically significant for most comparisons [1].
The safety findings are the practical part of the picture. The analysis linked tirzepatide to more injection site reactions, a consideration for people who find injections difficult or irritating [1]. It linked liraglutide to the highest risks of any adverse event and of stopping treatment because of one, which matters because a drug only helps while it is being taken [1]. Serious adverse events did not differ significantly between the drugs in this analysis [1].
The evidence base has limits. The trials included lasted at least a year, and the review does not establish safety or effectiveness beyond the follow-up periods studied [1]. People with diabetes were analyzed as a subgroup for the semaglutide dose comparison, and the significant advantage for the 7.2 mg dose appeared only there [1].
What happens next
No specific head-to-head trial or timeline was named [1]. The authors say further head-to-head trials and real-world studies are needed to refine dose selection and to assess long-term safety [1]. The review's results can be checked against its PROSPERO registration, CRD420251014401 [1].
Sources
Semaglutides.org provides information only, not medical advice. Talk to a licensed provider about your own care before making changes. Some telehealth links are affiliate links and are labeled where they appear.