Saxenda vs Wegovy: How Liraglutide and Semaglutide Differ
Saxenda vs Wegovy comes down to two molecules from one company. Saxenda holds liraglutide and Wegovy holds semaglutide, both made by Novo Nordisk, and both copy the gut hormone GLP-1.
The big difference is how long each one lasts. By their FDA labels, half of a liraglutide shot is gone in about 13 hours, while semaglutide takes about a week. In the one head to head trial, STEP 8, average weight loss was larger on semaglutide. Both are prescription drugs in the US, and brand Saxenda is due to be discontinued in January 2027.
Key facts
Drugs inside: Saxenda is liraglutide. Wegovy is semaglutide. Novo Nordisk makes both.
The key edit: Semaglutide swaps the building block at position 8 and carries a longer fatty tail, so it grips albumin harder.
Label half-life: About 13 hours for liraglutide, about 1 week for semaglutide, against 1.5 to 2 minutes for natural GLP-1.
Head to head: In STEP 8, average weight change over 68 weeks was -15.8% on semaglutide and -6.4% on liraglutide. Novo Nordisk funded it.
Status on 8 November 2026: Both prescription only. Brand Saxenda is listed as being discontinued, available until January 2027. Generic liraglutide is approved; generic semaglutide is not.
Sources: Saxenda label on DailyMed, version 22; Wegovy label on DailyMed, version 19; STEP 8, JAMA 2022 (PubMed abstract); Drugs@FDA, NDA 206321 (Saxenda); FDA drug shortage entry, liraglutide injection; openFDA Drugs@FDA query, liraglutide applications
What is the difference between Saxenda and Wegovy?
The difference between Saxenda and Wegovy is the molecule, and what that molecule does to the timing. Both brands are approved in the US for long-term weight management, with diet and more activity. Wegovy has since added two more uses. The table puts their FDA label facts next to each other.
| Label fact | Saxenda | Wegovy |
|---|---|---|
| Drug inside | Liraglutide | Semaglutide |
| Maker | Novo Nordisk | Novo Nordisk |
| Same molecule sold for type 2 diabetes as | Victoza (approved January 2010) | Ozempic (approved December 2017) |
| This brand approved | December 2014 | June 2021 |
| FDA-approved uses | Long-term weight management only | Long-term weight management, heart attack and stroke risk in people with heart disease, and the liver disease MASH |
| Ages on the weight label | Adults, and ages 12 and up with obesity who weigh more than 60 kg | Adults, and ages 12 and up with obesity |
| Changes from human GLP-1 | One swap (position 34) | Two swaps (positions 8 and 34) |
| Fatty tail at position 26 | 16 carbons, on a glutamic acid spacer | 18 carbons (a di-acid), on a water-loving spacer |
| Bound to blood proteins | More than 98% | More than 99%, to albumin |
| Half-life on the label | About 13 hours | About 1 week |
| Tablet version | None | Wegovy tablets, approved December 2025 |
| Status, 8 November 2026 | Prescription; FDA lists it as being discontinued, available until January 2027 | Prescription |
The half-life gap is also why the two labels give different use instructions. Those instructions belong to the prescriber and the label, so this page leaves them out and sticks to how the molecules work.
Sources: Saxenda label on DailyMed, version 22; Wegovy label on DailyMed, version 19; Victoza label on DailyMed, version 31; Ozempic label on DailyMed, version 20; Drugs@FDA, NDA 206321 (Saxenda); Drugs@FDA, NDA 215256 (Wegovy); FDA drug shortage entry, liraglutide injection
What do Saxenda and Wegovy copy?
Saxenda and Wegovy both copy GLP-1, a hormone your gut releases after you eat. It is one of the signals that help set appetite, and its receptors sit in several brain areas that control eating. Think of the hormone as a key and its receptor as a lock.
GLP-1 is a peptide, a short chain of amino acids. Liraglutide matches 97% of the human chain and semaglutide matches 94%. Most peptide drugs are given as shots, and our peptide reconstitution calculator handles the vial arithmetic for that whole group.
Natural GLP-1 has one big weakness. Two enzymes in the body, DPP-4 and NEP, cut it apart so fast that half is gone in 1.5 to 2 minutes. Both drugs are built to dodge that, in slightly different ways.
Sources: Wegovy label on DailyMed, version 19; Saxenda label on DailyMed, version 22
Liraglutide vs semaglutide: how are the molecules different?
Liraglutide vs semaglutide is a story of one extra swap and a longer tail. Each starts from the human GLP-1 chain. Liraglutide changes one building block, and semaglutide changes two. Both hang a fatty tail on the same spot, position 26, but the tails are not the same.
| Spot on the chain | Human GLP-1 | Liraglutide (Saxenda) | Semaglutide (Wegovy) |
|---|---|---|---|
| Position 8 | Alanine | Alanine (kept) | Aib, a lab-made building block |
| Position 34 | Lysine | Arginine | Arginine |
| Position 26 add-on | None | Palmitic acid (16 carbons) on a glutamic acid spacer | C18 fatty di-acid on a water-loving spacer |
| Match to human GLP-1 | 100% | 97% | 94% |
| How long half lasts | 1.5 to 2 minutes | About 13 hours | About 1 week |
The tail. A fatty tail lets the drug ride on albumin, a large protein in blood. Think of a balloon tied to a heavy backpack: it cannot float away. Over 98% of liraglutide in the blood is bound to proteins. Semaglutide uses a longer 18-carbon tail on a different link, and over 99% of it rides on albumin. Drug stuck to albumin slips through the kidneys more slowly and is guarded from enzymes.
The swap at position 8. This is the spot where DPP-4 cuts. Semaglutide puts a lab-made block called Aib there instead of natural alanine. Novo Nordisk scientists report that in lab tests, Aib was the only swap at this spot that both resisted DPP-4 and kept a tight grip on the lock. Liraglutide kept alanine, yet it is still partly protected. The same authors say its albumin grip or its sheer bulk may block the enzyme.
A slow start. The Saxenda label gives one more reason liraglutide lasts. Its molecules clump together where they are injected, so they seep into the blood slowly. The swap at position 34 has a job too. The Wegovy label says it makes sure only one fatty tail can attach.
The trade-off. In lab tests, semaglutide gripped the GLP-1 receptor about three times less tightly than liraglutide, but it gripped albumin harder. Lasting longer won out. The shot form of semaglutide has its own vial math tool, the semaglutide reconstitution calculator.
Sources: Saxenda label on DailyMed, version 22; Wegovy label on DailyMed, version 19; Lau and colleagues, J Med Chem 2015; Knudsen and Lau review, 2019
Where did the fatty tail idea come from?
The fatty tail idea goes back to the late 1990s. A 2019 review by two Novo Nordisk scientists says the approach was first described in 1998, with a short 8-carbon fatty acid. A 2000 paper from Novo Nordisk then tested a whole series of GLP-1 copies with fatty acids attached. The goal was to make them bind albumin and act longer.
From that work, the team judged palmitic acid on a glutamic acid link to be the best mix. Liraglutide was then picked as having the best overall properties. Semaglutide came next. Its 2015 discovery paper says the goal was to raise albumin grip even further and make the chain fully stable against enzymes.
Sources: Knudsen and Lau review, 2019; Knudsen and colleagues, J Med Chem 2000; Lau and colleagues, J Med Chem 2015
What do Saxenda and Wegovy do in the body?
Saxenda and Wegovy do the same things in the body, because they turn the same lock. GLP-1 receptors are found in the pancreas, gut, heart, lungs, kidneys and brain.
Blood sugar. The Victoza label says liraglutide triggers insulin when blood sugar is high, and that this eases off as sugar falls back toward normal. It also lowers glucagon when sugar is high and slows how fast the stomach empties.
Appetite. Both labels describe animal studies. Liraglutide turned up in brain areas that control appetite, including the hypothalamus. Semaglutide reached and switched on nerve cells in brain regions that control food intake.
Newer drugs add locks. Tirzepatide turns this GLP-1 lock plus a second one for GIP, as shown in our tirzepatide episode. Cagrilintide skips GLP-1 and copies a different meal hormone, amylin, covered in the cagrilintide episode.
Sources: Knudsen and Lau review, 2019; Victoza label on DailyMed, version 31; Saxenda label on DailyMed, version 22; Wegovy label on DailyMed, version 19
Victoza vs Ozempic: why does the Saxenda label say 2010?
Victoza vs Ozempic is the diabetes version of the same pairing: Victoza is liraglutide and Ozempic is semaglutide. That is also why the Saxenda label says "Initial U.S. Approval: 2010", four years before Saxenda existed. The year belongs to the molecule, and liraglutide was first approved as Victoza.
| Date | What happened |
|---|---|
| 25 January 2010 | Victoza, the first liraglutide brand, is approved for type 2 diabetes. It is a new molecular entity. |
| 23 December 2014 | Saxenda is approved for weight management in adults. FDA filed it as a new use of an approved molecule. |
| 5 December 2017 | Ozempic, the first semaglutide brand, is approved for type 2 diabetes. It is also a new molecular entity. |
| 4 December 2020 | Saxenda is extended to ages 12 and up with obesity. |
| 4 June 2021 | Wegovy is approved for weight management. FDA called it the first new drug for general obesity or overweight since 2014. |
| 8 March 2024 | Wegovy adds a heart use: lower risk of heart death, heart attack and stroke in adults with heart disease and obesity or overweight. |
| August 2025 | Wegovy adds MASH, a liver disease, with moderate to advanced scarring, under accelerated approval. |
| 22 December 2025 | Wegovy tablets are approved as a new form of the same drug. |
Victoza is approved to improve blood sugar in type 2 diabetes from age 10. It is also approved to cut the chance of a heart attack, stroke or heart death in adults who have both type 2 diabetes and heart disease. Ozempic is approved for adults with type 2 diabetes, for blood sugar, for heart risk, and to slow kidney decline in those with chronic kidney disease.
Wegovy now also comes as a tablet, explained step by step in our oral semaglutide episode. For the label-by-label story of the two semaglutide shots, see our Wegovy vs Ozempic guide.
Sources: Drugs@FDA, NDA 022341 (Victoza); Drugs@FDA, NDA 206321 (Saxenda); Drugs@FDA, NDA 209637 (Ozempic); Drugs@FDA, NDA 215256 (Wegovy); FDA notice on Saxenda for ages 12 and up, December 2020; FDA bulletin, 4 June 2021; FDA news release, 8 March 2024; FDA notice on Wegovy for MASH, August 2025; Victoza label on DailyMed, version 31; Ozempic label on DailyMed, version 20; Saxenda label on DailyMed, version 22
What did the STEP 8 trial find?
STEP 8 found that adults on semaglutide lost more weight on average than adults on liraglutide. Its authors note that no phase 3 trial had compared the two for weight management before. Before it, each drug had only beaten a placebo, a look-alike with no drug, in its own separate trial.
The trial ran 68 weeks at 19 US sites. Its 338 adults had overweight or obesity and no diabetes. Everyone got diet and activity counseling. People knew which of the two drugs they were on. What they did not know was whether they had the drug or its matching placebo.
| Measure | Semaglutide (126 people) | Liraglutide (127 people) | Placebo (85 people) |
|---|---|---|---|
| Average weight change at week 68 | -15.8% | -6.4% | -1.9% |
| Lost 10% of body weight or more | 70.9% | 25.6% | Not compared in this table |
| Lost 15% or more | 55.6% | 12.0% | Not compared in this table |
| Lost 20% or more | 38.5% | 6.0% | Not compared in this table |
| Had gut side effects | 84.1% | 82.7% | Not compared in this table |
| Stopped treatment, for any reason | 13.5% | 27.6% | Not compared in this table |
The surprise. A bigger average drop did not bring more stomach trouble. Gut side effects were close on both drugs. Yet about twice as many people stopped liraglutide, for any reason, as stopped semaglutide. The abstract does not split those stops by cause.
Each drug in its own trial. In SCALE, 3,731 people without type 2 diabetes took liraglutide or placebo for 56 weeks. On average they lost 8.4 kg on liraglutide and 2.8 kg on placebo. In STEP 1, 1,961 adults without diabetes were followed for 68 weeks. Their average change was -14.9% on semaglutide and -2.4% on placebo. These trials had different people and methods, so only STEP 8 compares the two drugs directly.
Who paid. Novo Nordisk, which makes both drugs, funded STEP 8, SCALE and STEP 1. For STEP 8, the paper says sponsor staff helped design the trial, analyze the data and write the report. Several authors worked for the company. These are averages for groups, not promises for any one person.
Sources: STEP 8, JAMA 2022 (PubMed abstract); STEP 8 full text, funding and sponsor role; SCALE, NEJM 2015; STEP 1, NEJM 2021
Saxenda vs Wegovy side effects: what do the labels say?
The side effects of Saxenda and Wegovy are mostly the same, and mostly in the gut. Both labels open their list of common reactions with nausea, diarrhea, vomiting and constipation. Only the order differs.
Other common reactions. The Saxenda list also has headache, low blood sugar, indigestion, tiredness, dizziness, belly pain, fever and stomach flu. It adds skin reactions where the shot goes in, and higher lipase, a gut enzyme, in blood tests. The Wegovy list also has headache, belly pain, dizziness, tiredness, indigestion, gas, bloating, burping, reflux, stomach flu and hair loss. It adds dysesthesia, an odd skin feeling, and low blood sugar in people who also have type 2 diabetes.
Boxed warning. Each label carries the FDA's strongest warning. Both drugs caused thyroid C-cell tumors in rodents, and whether they do this in people is still unknown. The labels rule both out for people with a past or family case of medullary thyroid cancer, or with the inherited condition MEN 2.
Pancreas and gallbladder. Both warn about acute pancreatitis, an inflamed pancreas, including fatal cases seen with GLP-1 drugs. Gallstones were more common than on placebo in each drug's trials: 2.2% vs 0.8% for Saxenda, and 1.6% vs 0.7% for the Wegovy shot. Those come from different trials, so they are not a head to head comparison.
A warning that came off. On 13 January 2026 the FDA asked makers to drop a warning about suicidal thoughts and behavior. It named the Saxenda, Wegovy and Zepbound labels, and said its review found no increased risk. Both current labels mark that section as removed in February 2026. A doctor is the one to say how these warnings fit a given patient.
Sources: Saxenda label on DailyMed, version 22; Wegovy label on DailyMed, version 19; FDA Drug Safety Communication, 13 January 2026
Are Saxenda and Wegovy still available, and is there a generic?
Both are still on the US market for now, with one end date in sight. On 8 November 2026, Drugs@FDA showed Saxenda, Victoza, Wegovy and Ozempic as prescription drugs. The FDA shortage list says brand Saxenda is being discontinued and will be available until January 2027. It gives the reason as a stop in making the drug, not a safety problem.
Generic liraglutide. Drugs@FDA lists 11 approved generic liraglutide applications, all prescription only. The first one referencing Victoza, from Hikma, was approved on 23 December 2024. The first referencing Saxenda, from Teva, followed on 27 August 2025. Liraglutide injection has been on the FDA shortage list since July 2023 and still shows as in shortage.
Generic semaglutide. None has full approval. One generic semaglutide shot, from Apotex, has a tentative approval dated 7 April 2026. A tentative approval does not allow it to be sold.
These listings change, so the dates above are the day we checked. Our medical review policy explains how approval and status facts are checked before they go on a page.
Sources: Drugs@FDA, NDA 206321 (Saxenda); Drugs@FDA, NDA 215256 (Wegovy); openFDA Drugs@FDA query, liraglutide applications; Drugs@FDA, ANDA 220314 (semaglutide, tentative); FDA drug shortage entry, liraglutide injection; FDA news release, 23 December 2024; FDA list of 2025 first generic approvals
What else do people ask about Saxenda vs Wegovy?
What is the difference between Saxenda and Wegovy?+
Saxenda holds liraglutide and Wegovy holds semaglutide. Both come from Novo Nordisk and both switch on the GLP-1 receptor. Semaglutide has an extra swap at position 8 and a longer fatty tail. So it lasts longer: its label half-life is about a week, against about 13 hours for liraglutide. Wegovy is also approved for heart risk and the liver disease MASH, while Saxenda covers weight only.
Is Wegovy stronger than Saxenda?+
STEP 8 is the one head to head trial. It followed 338 adults without diabetes for 68 weeks. Average weight change was -15.8% on semaglutide and -6.4% on liraglutide. Those are group averages from a trial Novo Nordisk paid for, and people knew which drug they got. They are not a forecast for any one person, and which drug suits someone is a call for their prescriber.
What is the difference between liraglutide and semaglutide?+
Both are lab-made copies of the gut hormone GLP-1. Liraglutide keeps 97% of the natural chain, with one swap and a 16-carbon fatty tail. Semaglutide keeps 94%, with two swaps and an 18-carbon tail that grips albumin harder. The FDA labels give liraglutide a half-life of about 13 hours and semaglutide about a week.
What is the difference between Saxenda and semaglutide?+
Saxenda does not contain semaglutide. It contains liraglutide, an older GLP-1 copy from the same company. Semaglutide is the drug in Wegovy and Ozempic. Liraglutide has one swap from human GLP-1, and semaglutide has two. Semaglutide also stays in the body much longer: about a week, against about 13 hours.
Can I lose 30 pounds in 3 months on Wegovy?+
No trial on this page answers that. STEP 1 and STEP 8 report weight change after 68 weeks, as a percentage of body weight, and the averages hide a wide spread from person to person. In STEP 1, average change on semaglutide was -14.9% at week 68. These are group results, not a target or a promise, and a prescriber is the right person to ask about expectations.
Why are people stopping Wegovy?+
Trials give part of the answer. In STEP 8, 13.5% of people on semaglutide stopped treatment for any reason, against 27.6% on liraglutide. The abstract does not list the reasons. In STEP 1, 4.5% on semaglutide stopped because of gut side effects, against 0.8% on placebo. Reasons outside trials are not measured in these sources.
What is the difference between Victoza and Ozempic?+
Victoza is liraglutide and Ozempic is semaglutide. They hold the same two drugs as Saxenda and Wegovy, but they are approved for type 2 diabetes, not weight. Victoza came first, in January 2010, and covers ages 10 and up. Ozempic came in December 2017 for adults. Both labels add a heart risk use, and Ozempic also has a kidney use in people with type 2 diabetes and chronic kidney disease.
How does liraglutide compare to Ozempic for weight loss?+
Ozempic is semaglutide, and its FDA label covers type 2 diabetes only, so weight loss is not one of its approved uses. The weight brands are Saxenda for liraglutide and Wegovy for semaglutide. STEP 8 tested the two drugs for weight in 338 adults without diabetes: after 68 weeks, body weight fell by 15.8% on average with semaglutide and by 6.4% with liraglutide. Those are group averages from a trial Novo Nordisk paid for, not a forecast for one person.
Is there a generic for Saxenda or Wegovy?+
For liraglutide, yes. On 8 November 2026 Drugs@FDA showed 11 approved generic liraglutide applications, all prescription only. The first one referencing Victoza was approved in December 2024, and the first referencing Saxenda in August 2025. For semaglutide, no generic has full approval. One has only a tentative approval, so it cannot be sold yet.
Is Saxenda being discontinued?+
Yes, for the brand. On 8 November 2026, the FDA shortage list said brand Saxenda is being discontinued. It stays available until January 2027. Liraglutide itself is not going away: generic liraglutide applications are approved. Wegovy is listed as a prescription drug with no such notice.
Can Saxenda and Wegovy be used together?+
Their labels say no. The Saxenda label says it is not recommended alongside other liraglutide products or any other GLP-1 drug. The Wegovy label says the same about other semaglutide products and other GLP-1 drugs.
Can you switch from Saxenda to Wegovy?+
That is a decision for a prescriber, and this page gives no switching steps. Both labels warn against using either one with another GLP-1 drug. So any change is planned with the person who prescribes it.
Do Saxenda and Wegovy have the same side effects?+
Mostly, because they work the same way. Both labels list nausea, diarrhea, vomiting and constipation among the most common side effects. Each label has the same kind of boxed warning, based on thyroid C-cell tumors in rats and mice, and both warn about pancreatitis and gallstones. In STEP 8, gut side effects were reported by 84.1% on semaglutide and 82.7% on liraglutide.
Do Saxenda or Wegovy come as a pill?+
Wegovy does. The FDA approved Wegovy tablets on 22 December 2025, and one label now covers the Wegovy shot and the tablets. Drugs@FDA lists Saxenda only as an injectable solution, with no tablet.
Why does the Saxenda label say 2010?+
The line "Initial U.S. Approval: 2010" marks the year the molecule was first approved, not the brand. Liraglutide was first approved as Victoza on 25 January 2010. Saxenda, the same molecule for weight, followed on 23 December 2014.
Sources: Saxenda label on DailyMed, version 22; Wegovy label on DailyMed, version 19; Victoza label on DailyMed, version 31; Ozempic label on DailyMed, version 20; STEP 8, JAMA 2022 (PubMed abstract); STEP 1, NEJM 2021; openFDA Drugs@FDA query, liraglutide applications; FDA drug shortage entry, liraglutide injection; Drugs@FDA, NDA 022341 (Victoza); Drugs@FDA, NDA 206321 (Saxenda)
What did we learn about Saxenda vs Wegovy?
Saxenda and Wegovy are one GLP-1 key cut two ways. Semaglutide guards position 8 against DPP-4 and holds on to albumin harder, so it lasts about a week instead of about 13 hours. In STEP 8 it brought a larger average weight drop, with gut side effects about as common. Brand Saxenda is on its way out, generic liraglutide is in, and generic semaglutide is still waiting.
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Nothing here is medical advice. We sum up what the labels, the FDA databases and the published trials report on Saxenda and Wegovy. Whether a prescription drug fits a person is a call for their own doctor.