Vial Guide

Liraglutide vs semaglutide

Both are Novo Nordisk GLP-1 drugs. Liraglutide is injected daily and semaglutide weekly, and in their head-to-head weight trial semaglutide led to more than twice the weight loss.

Liraglutide
Approved drugOnce daily
Semaglutide
Approved drugOnce weekly
Head-to-head trials
2

The short answer

Liraglutide (Saxenda, Victoza) and semaglutide (Wegovy, Ozempic) act on the same receptor, GLP-1. Liraglutide lasts about 13 hours in the body, so it’s injected once a day; semaglutide lasts about a week, so it’s injected once a week.

In STEP 8, adults with obesity lost 15.8% of body weight on semaglutide 2.4 mg weekly vs 6.4% on liraglutide 3 mg daily over 68 weeks, and fewer stopped treatment (13.5% vs 27.6%). In type 2 diabetes, semaglutide 1 mg also lowered HbA1c and weight more than liraglutide 1.2 mg (SUSTAIN 10). Liraglutide’s practical edge is availability: generic versions have been approved since 2024.

At a glance

FieldLiraglutideActive ingredient in Victoza and SaxendaSemaglutideActive ingredient in Ozempic and Wegovy
EvidenceApproved drugApproved drug
ClassGLP-1 receptor agonistGLP-1 receptor agonist
ApprovalApproved in the US as Victoza (type 2 diabetes in adults and children 10 and older, and heart-risk reduction) and Saxenda (weight management in adults and children 12 and older), plus generic versions of both. Novo Nordisk plans to discontinue the Saxenda brand in January 2027.Approved in the US as Wegovy (weight management, heart risk, MASH) and as Ozempic and Rybelsus (type 2 diabetes, including heart risk), as weekly injections and daily tablets.
Sport (WADA 2026)Not banned in sportNot banned in sport
Common dose0.6 → 1.8–3 mg daily0.25 → 2.4 mg weekly
FrequencyOnce dailyOnce weekly
CycleContinuousContinuous
RouteSubcutaneous injectionSubcutaneous injection
Half-lifeabout 13 hours Labelabout 1 week Label
Typical draw12 units5 mg with 1 mL, 0.6 mg5 units10 mg with 2 mL, 0.25 mg
Vial sizes or form5, 10 mg10, 20 mg
Human studies5 listedLargest: 9,340 people (2016)5 listedLargest: 17,604 people (2023)
Main cautions
  • Boxed warning for thyroid C-cell tumors. Not for anyone with a personal or family history of medullary thyroid carcinoma or MEN 2.
  • Nausea, diarrhea, constipation and vomiting are common, especially during the step-up. It slows stomach emptying, so tell the care team before surgery or sedation.
  • Pancreatitis, gallbladder disease, and kidney injury from dehydration are listed risks.
  • Boxed warning for thyroid C-cell tumors. Not for anyone with a personal or family history of medullary thyroid carcinoma or MEN 2.
  • Nausea, vomiting and constipation are common, especially after each step up.
  • Pancreatitis, gallbladder disease, and kidney injury from dehydration are listed risks.
Open LiraglutideOpen Semaglutide

Doses shown are what labels, trials or community reports reference, not recommendations. Each compound’s page has the full detail and sources.

Key differences

Dosing

Label

Liraglutide: daily, rising 0.6 mg a week to 3 mg (Saxenda) or to 1.2–1.8 mg (Victoza). Semaglutide: weekly, rising every 4 weeks to 2.4 mg (Wegovy) or 0.5–2 mg (Ozempic).

Weight loss

Trial

Head to head: 15.8% vs 6.4% at 68 weeks (STEP 8). In their own placebo-controlled trials: semaglutide 14.9% at 68 weeks; liraglutide 7.4% at 56 weeks (Saxenda label).

Stopping rule

Label

Saxenda’s label says adults who haven’t lost at least 4% of body weight by week 16 should stop, because meaningful loss is unlikely.

Generics and brands

Generic liraglutide has been approved since 2024, and Novo Nordisk plans to discontinue the Saxenda brand in January 2027. Semaglutide has no fully approved US generic: one received tentative approval in April 2026, which doesn’t allow it to be sold yet.

Side effects

Trial

The same GI pattern with both. In STEP 8, GI side effects were reported by 84.1% on semaglutide and 82.7% on liraglutide. In SUSTAIN 10, more people stopped semaglutide 1 mg for side effects (11.4% vs 6.6%).

Heart outcomes

Trial

Both lowered heart attacks, strokes and cardiovascular deaths in type 2 diabetes trials: liraglutide in LEADER (hazard ratio 0.87) and semaglutide in SUSTAIN-6 (0.74). Semaglutide also has SELECT, in people with heart disease and overweight but no diabetes.

Head-to-head studies

The 2 published trials that compared them directly.

  1. 2022338 people

    Weight fell 15.8% on semaglutide vs 6.4% on liraglutide (1.9% on placebo) in adults with overweight or obesity without diabetes; 13.5% vs 27.6% stopped treatment for any reason.

    Design
    Randomized open-label trial (phase 3b), with matched placebo groups
    Dose
    Semaglutide 2.4 mg weekly vs liraglutide 3 mg daily
    Length
    68 weeks

    Rubino et al., JAMA 2022 (STEP 8), PMID 35015037

  2. 2020577 people

    In type 2 diabetes, HbA1c fell 1.7 vs 1.0 points and weight 5.8 vs 1.9 kg; 11.4% vs 6.6% stopped because of side effects.

    Design
    Randomized open-label trial (phase 3b)
    Dose
    Semaglutide 1 mg weekly vs liraglutide 1.2 mg daily
    Length
    30 weeks

    Capehorn et al., Diabetes Metab 2020 (SUSTAIN 10), PMID 31539622

Taking them together

Two GLP-1 drugsLabel

Liraglutide and semaglutide both act on the GLP-1 receptor. The Wegovy and Zepbound labels say not to combine them with any other GLP-1 receptor agonist.

Source: Wegovy and Zepbound prescribing information, section 1

Open them in the stack check for sport status and one combined tracking checklist.

Questions

What is the difference between liraglutide and semaglutide?

Liraglutide (Saxenda, Victoza) and semaglutide (Wegovy, Ozempic) act on the same receptor, GLP-1. Liraglutide lasts about 13 hours in the body, so it’s injected once a day; semaglutide lasts about a week, so it’s injected once a week.

Is semaglutide better than liraglutide for weight loss?

In the head-to-head STEP 8 trial, yes: 15.8% vs 6.4% of body weight over 68 weeks at the full weight-loss doses (2.4 mg weekly vs 3 mg daily). Liraglutide’s advantages are generic availability and a shorter half-life (about 13 hours vs a week), so it leaves the body faster after stopping.

Can liraglutide and semaglutide be taken together?

The stack check flags two GLP-1 drugs. Liraglutide and semaglutide both act on the GLP-1 receptor. The Wegovy and Zepbound labels say not to combine them with any other GLP-1 receptor agonist. No published study has tested them together.

Which has more evidence in people, liraglutide or semaglutide?

Liraglutide is approved in the US; its page lists 5 key human studies. Semaglutide is approved in the US; its page lists 5 key human studies. They have been compared directly in 2 trials, described on this page.

Are liraglutide and semaglutide banned in sport?

Liraglutide and semaglutide aren’t banned. This follows the WADA 2026 Prohibited List; athletes should confirm with their anti-doping organization.

Sources

  • Rubino et al., semaglutide vs liraglutide, STEP 8 (JAMA 2022) PMID 35015037
  • Capehorn et al., semaglutide 1 mg vs liraglutide 1.2 mg, SUSTAIN 10 (Diabetes Metab 2020) PMID 31539622
  • Saxenda prescribing information, rev. 02/2026 (Novo Nordisk)
  • Wegovy prescribing information, rev. 06/2026 (Novo Nordisk)
  • Drugs@FDA: liraglutide and semaglutide abbreviated applications (checked October 2026)
  • Marso et al., LEADER trial (NEJM 2016) PMID 27295427
  • Marso et al., SUSTAIN-6 trial (NEJM 2016) PMID 27633186

Each compound’s page lists its full sources: Liraglutide, Semaglutide.

By Vial Guide editorsLast reviewed

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