Liraglutide and semaglutide are both GLP-1 medications made by Novo Nordisk. Liraglutide came first. Semaglutide came later and lasts much longer in the body. If your prescriber mentioned either one, this side-by-side guide will help you understand how they differ.
Key takeaways
- Liraglutide is taken once a day by injection. Semaglutide is taken once a week by injection, or once a day as a pill.
- Liraglutide brands are Victoza (type 2 diabetes) and Saxenda (weight management). Generic versions of both are now available.
- Semaglutide brands are Ozempic and Rybelsus (type 2 diabetes) and Wegovy (weight management and more).
- In the STEP 8 head-to-head trial, semaglutide led to more weight loss on average and fewer people stopped due to side effects.
- Both have similar side effect profiles and warnings. Your prescriber picks based on your needs, coverage and history.
Two drugs, same family
Both drugs copy the natural hormone GLP-1, which helps control blood sugar, slows stomach emptying and lowers appetite. Our guide to what a GLP-1 agonist is covers the basics.
The main difference is how long each lasts. Liraglutide's structure lets it work for about a day, so it is a daily shot. Semaglutide was designed to bind more strongly to a blood protein called albumin. That slows its breakdown so much that it has a half-life of about one week, which allows weekly dosing.
Side-by-side comparison
| Liraglutide | Semaglutide | |
|---|---|---|
| Brand names | Victoza, Saxenda (plus generics) | Ozempic, Wegovy, Rybelsus |
| How often | Once daily | Once weekly (injection) or once daily (tablet) |
| Form | Injection pen | Injection pen or tablet |
| Type 2 diabetes | Victoza: ages 10 and up | Ozempic and Rybelsus: adults |
| Weight management | Saxenda: adults and teens 12+ (over 60 kg) | Wegovy: adults and teens 12+ (injection); adults (tablet) |
| Heart risk reduction | Victoza: adults with type 2 diabetes and heart disease | Ozempic, Rybelsus, Wegovy (specific populations) |
| Other approvals | None beyond above | Ozempic: kidney disease in type 2 diabetes; Wegovy injection: MASH |
| Generic available | Yes | Check with pharmacist |
Approved uses differ by brand, not just by ingredient. Always check the current label for the exact product.
What the head-to-head trial found
The STEP 8 trial, published in JAMA in 2022, directly compared weekly semaglutide with daily liraglutide for weight management in adults with overweight or obesity who did not have diabetes. Over 68 weeks:
- Average weight loss was 15.8% with semaglutide and 6.4% with liraglutide.
- About 13.5% of people stopped semaglutide early for any reason, compared with 27.6% for liraglutide.
- About 3.2% stopped semaglutide because of side effects, compared with 12.6% for liraglutide.
- Stomach side effects were common with both (about 84% and 83%), mostly during or soon after dose increases.
These are averages. Some people do well on liraglutide, and some people do not tolerate semaglutide.
Side effects and warnings
Because they work the same way, the two drugs share most side effects: nausea, diarrhea, vomiting, constipation and belly pain. Both labels carry a boxed warning about thyroid C-cell tumors seen in rodents, and both warn about pancreatitis, gallbladder disease, low blood sugar when combined with certain diabetes drugs, and kidney problems from dehydration.
Both drugs start at a low dose and step up over time to reduce stomach symptoms. Liraglutide's step-up for weight management is shorter, about five weeks for adults. Semaglutide's step-up takes several months. Your prescriber sets the exact schedule. See GLP-1 titration.
Daily vs. weekly: which fits your life?
Some people prefer a weekly shot because there is less to remember. Others like a daily routine and find it easier to stay on track. A few practical points:
- Daily injections mean more pen needles to dispose of, so a sharps container helps.
- Weekly injections mean a missed dose matters more, since each dose covers a full week.
- Oral semaglutide avoids needles but has strict rules about taking it on an empty stomach. See oral semaglutide vs. injections.
Either way, a reminder system and a dose log help. The PepSteady app can track daily or weekly schedules.
Cost and access
Generic liraglutide is now sold in the US. Teva launched a generic of Victoza in 2024 and a generic of Saxenda in 2025, and other companies have followed. Generics can lower cost, especially if insurance does not cover brand-name weight-management drugs. Prices and coverage still vary a lot, so ask your pharmacist to compare options for your plan.
Which one is right for you?
There is no single answer. Your prescriber may consider:
- Your diagnosis (type 2 diabetes, weight management, heart disease, kidney disease).
- What your insurance covers.
- Whether you prefer daily or weekly dosing, or a pill.
- How you have tolerated GLP-1s before.
- Your health history, including thyroid and pancreas history.
The bottom line
Liraglutide and semaglutide work the same way, but semaglutide lasts longer, is taken less often and produced more weight loss on average in a head-to-head trial. Liraglutide now has generic options that may cost less. Talk with your prescriber about which fits your health, budget and routine.
Sources
- Wegovy prescribing information (FDA)
- Saxenda prescribing information (Drugs.com)
- STEP 8 trial summary (PACE-CME)
- FDA approves first generic GLP-1 indicated for weight loss (Healio)
- GLP-1 drug approvals: a breakdown (Becker's)
Frequently asked questions
Which works better for weight loss, liraglutide or semaglutide?
In the STEP 8 head-to-head trial, people on weekly semaglutide lost more weight on average than people on daily liraglutide over 68 weeks. Individual results vary, and your prescriber will weigh cost, coverage and your health history.
Is there a generic semaglutide in the US?
Generic liraglutide versions of Victoza and Saxenda are available in the US. Brand-name semaglutide is sold as Ozempic, Wegovy and Rybelsus. Check with your pharmacist for current generic availability, since this can change.
Can I switch from liraglutide to semaglutide?
People do switch, but only under a prescriber's guidance. The doses are not equivalent, and your prescriber will decide where to start and how to step up.