Semaglutide vs Liraglutide (Saxenda) for Weight Loss: What the Research Shows

*This article is for informational purposes only. It is not medical advice. Compounded semaglutide is not FDA-approved. Individual results vary. Both medications work best when combined with a reduced-calorie diet and increased physical activity. Speak with a licensed healthcare provider before starting, switching, or stopping any prescription medication.*

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If you are currently on liraglutide (Saxenda) for weight loss, or if your provider has mentioned it as an option, you may have started hearing more about semaglutide. It is in the same drug class. It works through the same basic mechanism. But according to the clinical evidence, the two medications are not equivalent.

In 2022, researchers published the STEP 8 trial in JAMA: the first large, randomized, head-to-head comparison of semaglutide 2.4 mg weekly versus liraglutide 3.0 mg daily in adults with overweight or obesity. The results were not close.

This guide explains what that trial found, how the two medications differ in practice, and what those differences mean for you.

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What Is Liraglutide (Saxenda)?

Liraglutide is a GLP-1 receptor agonist, a type of medication that mimics glucagon-like peptide-1, a gut hormone released after eating. GLP-1 signals the brain that you are full, slows how quickly your stomach empties, and stimulates insulin release when blood sugar rises.

Saxenda is the brand name for liraglutide 3.0 mg, formulated specifically for weight management. It received FDA approval in 2014 for chronic weight management in adults with obesity or overweight with at least one weight-related condition.

The landmark trial behind Saxenda's approval was the SCALE Obesity study. In that 56-week randomized controlled trial, Pi-Sunyer et al. found that liraglutide 3.0 mg daily produced an average weight loss of 8.0% compared to 2.6% for placebo (Wilding JPH et al., *N Engl J Med*, 2021; Pi-Sunyer X et al., *N Engl J Med*, 2015, PMID: 26510028). These were meaningful results at a time when few prescription options existed for obesity treatment.

Saxenda is given as a daily subcutaneous injection. The dose is gradually increased over five weeks to reduce gastrointestinal side effects, starting at 0.6 mg/day and reaching the full 3.0 mg/day maintenance dose.

Note on current availability: Novo Nordisk, the manufacturer of Saxenda, began phasing out Saxenda in the United States in late 2023 and 2024 as the market shifted toward Wegovy (semaglutide). If you have been on Saxenda and are looking for what comes next, semaglutide is the most clinically supported transition.

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What Is Semaglutide?

Semaglutide is also a GLP-1 receptor agonist. It works through the same general mechanism as liraglutide but is structurally different in ways that matter clinically: it has a longer half-life (allowing once-weekly dosing instead of daily), a higher binding affinity to the GLP-1 receptor, and a modified albumin-binding side chain that slows its breakdown in the body.

The FDA approved semaglutide 2.4 mg (as Wegovy) in 2021 for chronic weight management in adults with obesity or overweight with a weight-related condition.

The STEP 1 trial by Wilding et al. (PMID: 33567185), published in the *New England Journal of Medicine* in 2021, established semaglutide's efficacy benchmark:

• Average body weight reduction: 14.9% at 68 weeks
• Placebo group: 2.4%
• 86% of participants achieved at least 5% weight loss
• 50.5% achieved at least 15% weight loss

These results significantly exceeded what had been seen with liraglutide in the SCALE Obesity trial, though the two trials enrolled different populations under different protocols. A direct comparison requires a head-to-head study.

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The STEP 8 Trial: The Head-to-Head Data

The STEP 8 trial (Rubino DM et al., *JAMA*, 2022, PMID: 35015037) enrolled 338 adults with overweight or obesity, none of whom had type 2 diabetes. Participants were randomized to receive either once-weekly subcutaneous semaglutide 2.4 mg or once-daily subcutaneous liraglutide 3.0 mg for 68 weeks. Both groups also received lifestyle counseling.

The results at 68 weeks:

All differences were statistically significant (P<0.001). Semaglutide produced approximately 2.5 times greater weight loss than liraglutide over the same treatment period.

This was a direct, randomized comparison. Participants received the same behavioral support. The difference in outcomes reflects the difference between the medications, not differences in study design.

A 2026 real-world study by Cetiner et al. (*Diabetes, Metabolic Syndrome and Obesity*, PMID: 41938643) that compared tirzepatide, semaglutide, and liraglutide in adults without diabetes in clinical practice found semaglutide consistently outperformed liraglutide on weight loss outcomes, consistent with the STEP 8 findings.

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Side-by-Side Comparison

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How Side Effects Compare

Both medications belong to the same drug class, so their side effect profiles are similar. The most common side effects of both are gastrointestinal:

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Stomach discomfort

In STEP 8, nausea occurred in 44.4% of semaglutide participants and 39.0% of liraglutide participants. Vomiting was slightly more common with semaglutide (24.5% vs 17.4%). Most GI side effects occur during dose escalation and typically improve as your body adjusts.

A 2026 systematic review by Shokr et al. (*Pharmaceuticals*, PMID: 41599734) found broadly comparable gastrointestinal, renal, and pancreatic safety profiles across GLP-1 receptor agonists as a class, with no signal that semaglutide posed greater organ-level risks than liraglutide.

One practical note: because semaglutide reaches a higher maintenance dose over a longer titration period than liraglutide, there may be a longer window during which nausea is most noticeable. Most people find this manageable, particularly with dietary adjustments (eating smaller portions, avoiding high-fat meals, staying hydrated).

If you are switching from liraglutide to semaglutide, your provider will typically guide the transition to minimize overlap and manage the dose ramp-up period. Do not switch or stop medications without discussing the plan with your prescriber.

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The SELECT Trial: Semaglutide and Cardiovascular Health

One meaningful difference between the two medications is the cardiovascular outcomes data.

In 2023, Lincoff et al. published the SELECT trial in the *New England Journal of Medicine* (PMID: 37952131). This was a large randomized controlled trial in adults with established cardiovascular disease and overweight or obesity, none of whom had diabetes. Over about 33 months, semaglutide 2.4 mg reduced the risk of major adverse cardiovascular events (heart attack, stroke, or cardiovascular death) by 20% compared to placebo.

Liraglutide does not have an equivalent weight-management cardiovascular outcomes trial. The LEADER trial studied liraglutide in a diabetes population, but there is no SELECT-equivalent for liraglutide in a weight-management context.

For people with a history of cardiovascular disease, the SELECT data is clinically meaningful and may factor into your provider's treatment recommendation.

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Dosing and Convenience

This is a practical difference worth naming directly.

Liraglutide requires a daily injection. Semaglutide requires one weekly injection. For many people, moving from daily to weekly dosing makes medication adherence significantly easier. Fewer injections mean fewer missed doses, which translates to more consistent treatment exposure.

Real-world adherence data consistently shows higher long-term continuation rates with once-weekly GLP-1 medications compared to daily formulations, which is one reason why weekly dosing has become the standard for newer GLP-1 therapies.

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Who Should Consider Switching to Semaglutide?

If you are currently on liraglutide (Saxenda) and wondering whether semaglutide would work better for you, here are the situations where that conversation with your provider is worth having:

You are not seeing the results you expected. If you have been on liraglutide at the full maintenance dose for several months and have not achieved meaningful weight loss, semaglutide's stronger efficacy profile may offer a better response.

Your provider is managing or transitioning your Saxenda supply. With Saxenda being phased out in the US, many people currently on liraglutide will need to transition to another medication. Semaglutide is the most clinically established alternative in the same class.

You find daily injections difficult to maintain. Switching to a once-weekly medication can improve adherence without any change in the mechanism of action.

You have cardiovascular risk factors. The SELECT trial data may make semaglutide a preferred option for people with established cardiovascular disease.

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FAQ

Is semaglutide stronger than liraglutide (Saxenda)? The clinical evidence says yes. In the STEP 8 head-to-head trial (PMID: 35015037), semaglutide 2.4 mg weekly produced an average weight loss of 15.8% versus 6.4% for liraglutide 3.0 mg daily over 68 weeks. That is roughly 2.5 times greater weight loss in the same patients over the same period.

Can I switch directly from Saxenda to semaglutide? A transition is generally feasible since both are GLP-1 receptor agonists, but the specific transition plan (timing, whether to stop one before starting the other, starting dose for semaglutide) should be worked out with your prescriber. Do not make medication changes on your own.

Does Prescriva offer semaglutide as an alternative to Saxenda? Yes. Prescriva offers compounded semaglutide starting at $159 per month. If you are on Saxenda and want to explore semaglutide, you can start an online assessment to discuss your options with a licensed provider.

Are the side effects of semaglutide worse than Saxenda? Both medications share a similar gastrointestinal side effect profile. In the STEP 8 trial, nausea rates were comparable (44.4% semaglutide vs 39.0% liraglutide). Most side effects occur during the dose escalation period and tend to improve over time.

Is liraglutide still available in the US? Saxenda (liraglutide 3.0 mg) availability in the US has been substantially reduced as Novo Nordisk shifted supply to Wegovy (semaglutide). Check with your pharmacy or provider for current availability. Many people previously on Saxenda are transitioning to semaglutide.

Which GLP-1 is right for me if I have heart disease? Semaglutide has a dedicated cardiovascular outcomes trial (SELECT, PMID: 37952131) showing a 20% reduction in major cardiac events in adults with established cardiovascular disease. This data does not exist for liraglutide in a weight-management population. If cardiovascular risk is a factor in your treatment decisions, discuss the SELECT data with your provider.

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Summary

Semaglutide and liraglutide are both GLP-1 receptor agonists with demonstrated weight loss efficacy. But based on the direct comparison in the STEP 8 trial, semaglutide produces significantly greater weight loss, roughly 2.5 times as much on average, with the added benefits of once-weekly dosing and a strong cardiovascular outcomes dataset from the SELECT trial.

For most people considering GLP-1 weight loss therapy today, whether starting fresh or transitioning from Saxenda, semaglutide represents the more effective option in the same drug class.

As with any prescription medication, the right choice depends on your full medical picture, other medications you take, and your provider's clinical judgment. Use this information to have a more informed conversation with your care team.

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*This article is for informational purposes only and does not constitute medical advice. Clinical trial results cited are from studies of brand-name semaglutide and brand-name liraglutide; results with compounded formulations may differ. Consult your licensed healthcare provider before making any changes to your treatment.*

Sources:

• Pi-Sunyer X et al. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management. *N Engl J Med*. 2015. PMID: 26510028
• Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. *N Engl J Med*. 2021. PMID: 33567185
• Rubino DM et al. 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. PMID: 35015037
• Lincoff AM et al. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes. *N Engl J Med*. 2023. PMID: 37952131
• Cetiner S et al. Real-World Effectiveness and Safety of Tirzepatide, Semaglutide, and Liraglutide in Adults with Overweight or Obesity without Diabetes: A Comparative Study. *Diabetes Metab Syndr Obes*. 2026. PMID: 41938643
• Shokr H et al. Comparative Safety of GLP-1 Receptor Agonists Across Gastrointestinal, Renal and Pancreatic Systems. *Pharmaceuticals (Basel)*. 2026. PMID: 41599734