Home / Comparisons / Semaglutide vs Liraglutide: What the Head-to-Head Shows
Semaglutide vs Liraglutide: What the Head-to-Head Shows
One head-to-head trial, two FDA-approved GLP-1 drugs. How semaglutide and liraglutide compare on weight, labels, heart trials, safety and supply.
On this page
Side by side
| Question | Semaglutide | Liraglutide |
|---|---|---|
| U.S. status | ||
| Strongest evidence | Human trials | Human trials |
| Status verified |
Both are FDA-approved, and both brand-name versions come from the same manufacturer. One trial has compared them directly on weight. Heart, kidney and liver questions have no head-to-head answer.
Key takeaways
- In STEP 8, the only head-to-head trial of the two drugs for weight management, adults without diabetes lost 15.8% of body weight on weekly semaglutide and 6.4% on daily liraglutide over 68 weeks.
- The trial was open-label between the two drugs and was sponsored by Novo Nordisk, which makes both. The trial did not compare heart outcomes.
- Their approved uses overlap but are not identical. Semaglutide’s labels include uses that liraglutide’s do not: kidney outcomes in type 2 diabetes with chronic kidney disease, fatty liver disease (MASH), and fewer cardiovascular events in people with obesity and heart disease.
- Both carry a boxed warning for thyroid C-cell tumors seen in rodents.
- Supply differs. FDA’s shortage list shows no semaglutide product in shortage. Liraglutide is on the list, with status that differs by product.
- “Better” depends on the goal and the person. That is a decision for a prescriber, using the labels.
Which one causes more weight loss?
STEP 8 is the direct comparison in people without diabetes. Each drug was compared with placebo double-blind, with placebo groups pooled, and the two drugs were compared with each other open-label. It enrolled adults with obesity, or overweight plus at least one weight-related condition, and ran 68 weeks.
| Measure | Semaglutide (n=126) | Liraglutide (n=127) |
|---|---|---|
| Average weight change | −15.8% | −6.4% |
| Lost at least 10% of body weight | 70.9% | 25.6% |
| Lost at least 15% | 55.6% | 12.0% |
| Lost at least 20% | 38.5% | 6.0% |
| Stopped treatment (any reason) | 13.5% | 27.6% |
| Gastrointestinal side effects | 84.1% | 82.7% |
| Serious adverse events | 7.9% (10 of 126) | 11.0% (14 of 127) |
Source: STEP 8 and its ClinicalTrials.gov record. The difference in weight change was 9.4 percentage points (95% CI 6.8 to 12.0 points). The pooled placebo group (n=85) lost 1.9%. More people stopped liraglutide than semaglutide (27.6% vs 13.5%), and gastrointestinal side effects were common with both (about 83% to 84%).
Four cautions:
- Sponsor. Novo Nordisk sponsored the trial and makes both drugs. That is context, not a flaw.
- Open-label between the drugs, and different schedules. One drug is weekly and the other daily, so the difference in who stopped treatment may reflect the schedule as well as the drug.
- Dose handling differed. The semaglutide arm allowed a lower dose for people who could not tolerate the target dose. The liraglutide arm required stopping and restarting instead.
- What it did not measure. The trial did not compare heart outcomes. The serious-event numbers are small and were not what the trial was built to settle.
Can the other trials be lined up?
No. The big trials for each drug were run separately, in different people, for different lengths of time and with different units. In SCALE, liraglutide produced −8.4 kg vs −2.8 kg on placebo at 56 weeks; in STEP 1, semaglutide produced −14.9% vs −2.4% on placebo at 68 weeks. Use STEP 8 for the comparison and these only as background.
How do the heart trials compare?
They are not head-to-head. Each tested one drug against a comparison group, in a different population.
| Trial | Drug | Who | Result |
|---|---|---|---|
| LEADER | Liraglutide | 9,340 people with type 2 diabetes at high cardiovascular risk | Major cardiovascular events 13.0% vs 14.9%; hazard ratio 0.87 (95% CI 0.78–0.97) |
| SUSTAIN 6 (per the Ozempic label) | Semaglutide | 3,297 people with type 2 diabetes and atherosclerotic cardiovascular disease; at least 2 years of follow-up | Hazard ratio 0.74 (95% CI 0.58–0.95) |
| SELECT | Semaglutide | 17,604 adults with cardiovascular disease and overweight or obesity, without diabetes | 6.5% vs 8.0%; hazard ratio 0.80 (95% CI 0.72–0.90) |
SUSTAIN 6’s primary analysis tested whether semaglutide was no worse than placebo (a non-inferiority margin of 1.3), though the Ozempic label says the drug “significantly reduced the occurrence of MACE.” The populations, comparison groups and follow-up differ, so the hazard ratios cannot be ranked against each other. Only semaglutide’s labels include a cardiovascular indication for adults with cardiovascular disease and obesity or overweight (Wegovy label).
How do their approved uses differ?
| Use | Semaglutide | Liraglutide |
|---|---|---|
| Weight management | Wegovy: adults with obesity, or overweight plus a weight-related condition, and children 12 and older with obesity | Saxenda: adults with obesity, or overweight plus a weight-related condition, and children 12 and older who weigh more than 60 kg and have obesity |
| Blood sugar control in type 2 diabetes | Ozempic and Rybelsus | Victoza, from age 10 |
| Fewer major cardiovascular events | Wegovy (adults with cardiovascular disease and obesity or overweight); Ozempic (type 2 diabetes with established cardiovascular disease); Rybelsus (high-risk type 2 diabetes) | Victoza (adults with type 2 diabetes and established cardiovascular disease) |
| Kidney outcomes in type 2 diabetes with chronic kidney disease | Ozempic | — |
| Fatty liver disease with moderate-to-advanced scarring (MASH F2–F3) | Wegovy, under accelerated approval | — |
Sources: Wegovy (rev. 06/2026), Ozempic (version effective June 2026), Saxenda (rev. 06/2026) and Victoza (rev. 10/2025). Ozempic has no weight indication. For that split, see Wegovy vs Ozempic. Each drug is covered in its own guide: semaglutide and liraglutide. Dosing is set by each label and your prescriber. This guide does not give doses.
What about muscle?
In a 2026 meta-analysis of randomized trials, lean mass was 35.2% of the weight lost with semaglutide and 26.8% with liraglutide. We read the abstract only, and the figures come from pooling different trials, so they do not show how the two drugs compare head to head. We did not find a head-to-head body-composition result. Lean mass is not the same as muscle. See what the data show on GLP-1 muscle loss.
How do the risks compare?
Both labels carry the same boxed warning.
| Semaglutide (Wegovy label) | Liraglutide (Saxenda label) | |
|---|---|---|
| Boxed warning | Thyroid C-cell tumors in rodents; relevance to humans not determined. Contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2 | Same |
| Other warnings | Acute pancreatitis, gallbladder disease, low blood sugar with insulin or similar drugs, acute kidney injury from dehydration, severe gastrointestinal reactions, hypersensitivity, diabetic retinopathy complications, increased heart rate, lung aspiration during anesthesia or deep sedation | Pancreatitis, gallbladder disease, low blood sugar, increased heart rate, kidney injury from fluid loss, severe gastrointestinal reactions, hypersensitivity, lung aspiration during anesthesia or deep sedation |
| Suicidal behavior and ideation warning | Removed in February 2026 | Removed in February 2026 |
The Saxenda label says using it with another liraglutide product or with any other GLP-1 drug is not recommended. In STEP 8, gastrointestinal side effects were common with both drugs (84.1% and 82.7%).
How do supply and compounding differ?
- Semaglutide. FDA’s drug shortage list shows no semaglutide product in shortage; it records only some Rybelsus tablet strengths as “to be discontinued.”
- Liraglutide. It remains on the list, but the status differs by product. As of Nov. 4, 2026, FDA lists Victoza and Saxenda with limited availability and several generic versions as available. See our liraglutide guide.
- Compounded versions of either drug are not FDA-approved. FDA does not review compounded drugs for safety, effectiveness or quality before they are marketed, and FDA says a compounded product should not be described as a generic or as the same as an approved drug.
- On May 1, 2026, FDA proposed not including either drug on its 503B bulk substances list. We found no final rule as of Nov. 4, 2026.
For the rules on compounded semaglutide, see what FDA says about compounded GLP-1 drugs. Apart from the 503B proposal above, we did not find an FDA statement on compounded liraglutide by name, so we make no claim about it.
Which claims are not supported?
- “STEP 8 shows semaglutide is safer.” The trial did not compare heart outcomes, and the difference in stopping treatment may reflect the weekly versus daily schedule.
- “The SCALE and STEP 1 results show the gap.” Different people, lengths and units. Use STEP 8.
- “LEADER beat SUSTAIN 6” or the reverse. They are different trials in different groups, not a comparison.
- “A generic is the same as a compounded version.” FDA approves generics. It does not approve compounded products.
- “Because it is in the same family, liraglutide can replace semaglutide for any use.” The labels have different indications.
What should you ask your doctor?
- Which of these is approved for my goal: weight, blood sugar, heart risk, kidney outcomes or liver disease?
- Do I have a personal or family history of medullary thyroid carcinoma or MEN 2? (It rules out both.)
- Have I had pancreatitis or gallbladder disease?
- Is the product I am offered FDA-approved or compounded, and who makes it?
- If the product I was prescribed is hard to find, what are my options?
We do not give doses, and we do not recommend products or sellers.
Frequently asked questions
Which is more effective for weight loss, semaglutide or liraglutide?
In STEP 8, the only head-to-head trial of the two drugs for weight management, adults without diabetes lost 15.8% of body weight on weekly semaglutide and 6.4% on daily liraglutide over 68 weeks. The trial was open-label between the two drugs and was sponsored by Novo Nordisk, which makes both.
Has anyone compared them on heart outcomes?
We found no trial comparing them directly on heart outcomes. LEADER (liraglutide) and SUSTAIN 6 and SELECT (semaglutide) tested each drug in different populations.
Are semaglutide and liraglutide the same drug?
No. They are different active ingredients with different approved uses, though both are GLP-1 drugs.
Can I take both?
The Saxenda label says using it with another liraglutide product or with any other GLP-1 drug is not recommended. Ask your prescriber about your situation.
Is liraglutide in shortage?
Liraglutide remains on FDA’s shortage list. FDA lists Victoza and Saxenda with limited availability and several generic versions as available. FDA’s list shows no semaglutide product in shortage.
From Best Peptides Today
Sources we checked
- STEP 8: semaglutide vs liraglutide for weight management, Rubino 2022, JAMA (PubMed)PubMed. Accessed .
- ClinicalTrials.gov NCT04074161 (STEP 8)ClinicalTrials.gov. Accessed .
- STEP 1 trial (PubMed)PubMed. Accessed .
- SCALE trial (PubMed)PubMed. Accessed .
- LEADER trial (PubMed)PubMed. Accessed .
- SELECT trial (PubMed)PubMed. Accessed .
- ClinicalTrials.gov NCT01720446 (SUSTAIN 6)ClinicalTrials.gov. Accessed .
- Wegovy prescribing information (DailyMed, rev. 06/2026)FDA. Accessed .
- Ozempic prescribing information (DailyMed, version effective June 2026)FDA. Accessed .
- Saxenda prescribing information (DailyMed, rev. 06/2026)FDA. Accessed .
- Victoza prescribing information (DailyMed, rev. 10/2025)FDA. Accessed .
- Eisa 2026: meta-analysis of lean mass with GLP-1 drugs (PubMed)PubMed. Accessed .
- FDA drug shortages listFDA. Accessed .
- Federal Register: proposed 503B bulk drug substances list (May 1, 2026)Other. Accessed .
- FDA: telehealth companies and promoting compounded drugsFDA. Accessed .
Written and maintained by the Best Peptides For Editorial Team. How we rate evidence.