Liraglutide vs semaglutide

Liraglutide and semaglutide activate the same GLP-1 receptor. Direct trials found larger average weight and blood-glucose reductions with semaglutide under the protocols tested. The comparison explains those trials, formulation differences, tolerability and separate cardiovascular evidence.

Research reviewed October 15, 2026. Educational information only.

Two medicines acting on the same receptor

Liraglutide and semaglutide activate the receptor for glucagon-like peptide-1, or GLP-1, a hormone released by the gut after eating. This signal helps the pancreas release insulin when blood glucose is high and helps regulate appetite and food intake. Both medicines were modified to persist much longer than the body’s own GLP-1, although their persistence and available formulations differ.

Those similarities make a direct comparison useful: researchers can ask whether one treatment produces a larger change in comparable groups of people, over the same period, with the same outcome measured. Two trials provide that comparison in different settings. STEP 8 examined weight management in adults without diabetes; SUSTAIN 10 examined blood-glucose control in adults with type 2 diabetes. Their findings are easiest to understand when each trial’s participants and tested formulations stay together. The official Saxenda and Wegovy labels explain the underlying pharmacology.

The main differences

STEP 8: the direct weight-loss trial

Rubino and colleagues (2022) enrolled 338 adults with overweight or obesity who did not have diabetes. Participants received diet and activity counseling and were randomly assigned to semaglutide, liraglutide or a matching placebo. The active groups contained 126 and 127 people, respectively; the two placebo groups contained 85 people in total. Treatment lasted 68 weeks, followed by seven weeks of follow-up.

The protocol compared semaglutide 2.4 mg injected under the skin once weekly with liraglutide 3.0 mg injected once daily. These amounts identify the trial treatments. Participants and investigators knew which active medicine had been assigned, while each medicine was blinded against its matching placebo. The main analysis included follow-up after people stopped treatment or began another weight intervention; missing measurements were estimated using the paper’s stated methods.

Estimated average weight loss at 68 weeks was 15.8% with semaglutide and 6.4% with liraglutide. The difference was 9.4 percentage points, with a 95% confidence interval from 6.8 to 12.0 points in semaglutide’s favor. The observed numbers reaching larger weight-loss thresholds are shown below; 117 participants in each active group had a week-68 weight measurement. These results describe average responses to the tested treatments; the study also documented substantial variation between individual participants.

Why treatment discontinuation needs context

Staying on a treatment is part of the clinical result. In STEP 8, 13.5% of participants assigned to semaglutide and 27.6% assigned to liraglutide permanently stopped treatment for any reason. Gastrointestinal events were common in both groups: 84.1% and 82.7%, respectively. A person reporting nausea or another digestive event was counted differently from a person permanently stopping treatment, so those percentages answer separate questions.

The protocol also handled poor tolerance differently. Semaglutide recipients who could not tolerate the target amount could receive a lower maintenance amount. Liraglutide recipients who could not tolerate its target amount stopped treatment and could restart with gradual escalation. The investigators identified that difference as a possible contributor to more permanent discontinuation with liraglutide.

The diabetes trial discussed next produced a different adverse-event pattern: digestive events and stopping because of an adverse event occurred more often with semaglutide. A practical comparison therefore needs the actual formulation, amount, population and stopping rules, as well as the name of the molecule. STEP 8 and SUSTAIN 10 provide that context.

SUSTAIN 10: blood glucose and weight in type 2 diabetes

Capehorn and colleagues’ SUSTAIN 10 trial randomly assigned 577 adults with type 2 diabetes who were already taking one to three oral diabetes medicines. Over 30 weeks, it compared weekly semaglutide 1.0 mg with daily liraglutide 1.2 mg, both injected under the skin. Participants and investigators knew the assignment.

The main measurement was HbA1c, the proportion of hemoglobin carrying glucose, which reflects blood-glucose exposure over preceding months. Starting from an average HbA1c of 8.2%, the reported decreases were 1.7 percentage points with semaglutide and 1.0 point with liraglutide. The modeled between-group difference was 0.69 percentage points in semaglutide’s favor (95% confidence interval 0.56–0.82). Average body weight fell by 5.8 kg and 1.9 kg, respectively; the modeled difference was 3.83 kg (95% confidence interval 3.09–4.57).

Gastrointestinal events were reported by 43.9% of semaglutide recipients and 38.3% of liraglutide recipients. Adverse events led to premature treatment discontinuation in 11.4% and 6.6%, respectively. SUSTAIN 10 used a lower liraglutide amount than STEP 8 and followed a different population for a shorter period. Its glucose and weight findings belong to that comparison.

Pharmacokinetics and available formulations

The prescribing information reports an elimination half-life of approximately 13 hours for liraglutide after injection under the skin and approximately one week for semaglutide. Half-life describes the time taken for the measured amount in blood to fall by half during elimination. The longer persistence of semaglutide helps explain its weekly injection formulation; liraglutide’s weight-management injection is given daily.

Absorption also matters. Current Wegovy labeling includes semaglutide tablets and a higher-strength injection presentation, whereas STEP 8 tested the weekly injection protocol described above. Neither oral semaglutide nor the 7.2 mg injection was compared with liraglutide in STEP 8. The Wegovy and Saxenda labels provide the product-specific absorption and elimination information. A half-life comparison helps explain drug design; the direct trials measure the actual changes in weight and glucose.

Cardiovascular outcomes come from separate trials

The larger cardiovascular trials used placebo controls and enrolled different patient groups. In LEADER, 9,340 people with type 2 diabetes at high cardiovascular risk were assigned to liraglutide or placebo. Over a median 3.8 years, cardiovascular death, nonfatal heart attack or nonfatal stroke occurred in 13.0% and 14.9%, respectively (hazard ratio 0.87; 95% confidence interval 0.78–0.97).

SELECT enrolled 17,604 adults with established cardiovascular disease and overweight or obesity who did not have diabetes. The same three-part cardiovascular outcome occurred in 6.5% with semaglutide and 8.0% with placebo (hazard ratio 0.80; 95% confidence interval 0.72–0.90), during a mean follow-up of 39.8 months.

Each trial supports a benefit against its own placebo group. Their different populations, background risks and follow-up prevent a reliable ranking of liraglutide against semaglutide from those percentages alone. A direct comparison of cardiovascular events would need a shared trial setting. The full compound profiles explain the separate organ-specific studies in more detail.

Safety and tolerability beyond the trial averages

Both official labels describe frequent gastrointestinal effects and warnings concerning pancreatitis, gallbladder disease, increased heart rate and kidney injury associated with dehydration. Both carry a boxed warning about thyroid C-cell tumors observed in rodents; whether that finding translates to these tumors in people remains uncertain. The labels contraindicate use in people with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2.

The full prescribing information also addresses interactions, pregnancy and other circumstances that change treatment decisions. A comparison of trial averages cannot determine which medicine is appropriate for a particular person. The current liraglutide and semaglutide labels should accompany any clinical discussion.

Frequently asked questions

Profiles and related reading

References

1. Rubino DM, Greenway FL, Khalid U, O’Neil PM, Rosenstock J, Sørrig R, Wadden TA, Wizert A, Garvey WT; STEP 8 Investigators. Effect of Weekly Subcutaneous Semaglutide vs Daily Liraglutide on Body Weight in Adults With Overweight or Obesity Without Diabetes: The STEP 8 Randomized Clinical Trial. JAMA. 2022;327(2):138–150. doi:10.1001/jama.2021.23619.

   Original randomized trial report. Methods; Table 2; supportive outcomes; adverse events; limitations.

2. Capehorn MS, Catarig AM, Furberg JK, Janez A, Price HC, Tadayon S, Vergès B, Marre M. Efficacy and safety of once-weekly semaglutide 1.0mg vs once-daily liraglutide 1.2mg as add-on to 1-3 oral antidiabetic drugs in subjects with type 2 diabetes (SUSTAIN 10). Diabetes & Metabolism. 2020;46(2):100–109. doi:10.1016/j.diabet.2019.101117.

   Original randomized trial report. Original abstract; methods, results and adverse-event comparisons.

3. Novo Nordisk. WEGOVY (semaglutide) injection and tablets: U.S. prescribing information. DailyMed. Current listing accessed October 15, 2026.

   Official prescribing information. Sections 1, 3, 4–5 and 12.1–12.3.

4. Novo Nordisk. SAXENDA (liraglutide) injection: U.S. prescribing information. Revised June 2026. DailyMed. Accessed October 15, 2026.

   Official prescribing information. Sections 1, 4–5 and 12.1–12.3; current page highlights revised 6/2026.

5. Marso SP, Daniels GH, Brown-Frandsen K, et al.; LEADER Steering Committee and Investigators. Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes. New England Journal of Medicine. 2016;375:311–322. doi:10.1056/NEJMoa1603827.

   Original randomized trial report. Original abstract; primary cardiovascular outcome and follow-up.

6. Lincoff AM, Brown-Frandsen K, Colhoun HM, et al.; SELECT Trial Investigators. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. New England Journal of Medicine. 2023;389:2221–2232. doi:10.1056/NEJMoa2307563.

   Original randomized trial report. Original abstract; population and primary cardiovascular result.