Victoza and Ozempic are two Novo Nordisk diabetes injections built on different molecules: liraglutide, injected daily, and semaglutide, injected weekly. They have been compared directly in one trial, SUSTAIN 10. Over 30 weeks, HbA1c fell 1.7 points on semaglutide and 1.0 on liraglutide, and weight fell 5.8 kg against 1.9 kg. More people stopped semaglutide because of side effects. The trial has one limit most summaries leave out: it tested liraglutide at 1.2 mg, below Victoza's 1.8 mg maximum.
This page reads the trial from its posted registry results and its publication, and the two drugs' current US labels from DailyMed. Records were read on 17 October 2026. It reports what the documents say; it does not advise on treatment.
The two drugs at a glance
| Victoza | Ozempic | |
|---|---|---|
| Molecule | Liraglutide | Semaglutide |
| Injection | Once daily | Once weekly (365 against 52 injections a year) |
| Label strengths | 0.6, 1.2 and 1.8 mg | 0.25, 0.5, 1 and 2 mg |
| Who it is approved for | Adults and children aged 10+ with type 2 diabetes | Adults with type 2 diabetes |
| Heart indication | Yes (LEADER trial) | Yes (SUSTAIN 6) |
| Kidney indication | No | Yes: reducing sustained eGFR decline, kidney failure and cardiovascular death in type 2 diabetes with chronic kidney disease |
| Weight-management sibling | Saxenda (liraglutide 3.0 mg) | Wegovy (semaglutide 2.4 mg and 7.2 mg) |
Sources: VICTOZA label, Novo Nordisk, effective 2025-10-14; OZEMPIC label, Novo Nordisk, effective 2026-06-01, sections 1 and 2; read on DailyMed 2026-10-17. Injections per year: our arithmetic.
The full Victoza record — its approval, LEADER, the generic copies and the shortage entry — is on Victoza, read from its label; Ozempic's is on what Ozempic is.
SUSTAIN 10, the head-to-head trial
SUSTAIN 10 (NCT03191396) was a phase 3b, open-label trial: participants and investigators knew which drug was given. It randomised 577 adults with type 2 diabetes, HbA1c 7.0% to 11.0%, already on one to three oral diabetes medicines, to semaglutide 1.0 mg weekly or liraglutide 1.2 mg daily, and ran from 2017 to its completion in August 2018. Novo Nordisk, which makes both, sponsored it.
| Outcome at week 30 | Semaglutide 1.0 mg weekly | Liraglutide 1.2 mg daily | Difference |
|---|---|---|---|
| HbA1c change (baseline 8.2%) | -1.7 points | -1.0 points | -0.69 (95% CI -0.82 to -0.56) |
| Body weight change (baseline 96.9 kg) | -5.8 kg | -1.9 kg | -3.83 kg (95% CI -4.57 to -3.09) |
| Fasting glucose change | -2.65 mmol/L | -1.46 mmol/L | — |
| Gastrointestinal side effects | 43.9% | 38.3% | — |
| Stopped early because of side effects | 11.4% | 6.6% | — |
| Serious adverse events (registry) | 17 of 289 (5.9%) | 22 of 287 (7.7%) | — |
Sources: Capehorn et al., Diabetes & Metabolism 2020 (efficacy, gastrointestinal and discontinuation figures); ClinicalTrials.gov NCT03191396 posted results (fasting glucose, serious adverse events; percentages our arithmetic), read 2026-10-17. The registry lists liraglutide's HbA1c change as -1.1 points and weight change as -2.0 kg, the publication as -1.0 and -1.9; the treatment differences are identical in both.
Three things the table does not say on its own.
- The liraglutide dose. The authors chose 1.2 mg because it was "the current most frequently prescribed liraglutide dose in Europe", and 1.0 mg as the most likely semaglutide dose. Victoza's US label goes to 1.8 mg, and Ozempic's to 2 mg. So SUSTAIN 10 compares common European doses, not each drug's maximum.
- Side effects cut the other way. The drug that lowered blood sugar and weight more also led more people to stop: 11.4% against 6.6%. Serious adverse events, by contrast, were numerically fewer on semaglutide (17 against 22 people), the same direction as in STEP 8 at the weight-management doses (see below).
- Open-label design. Knowing which drug one is on can affect how side effects are reported and how readily treatment is stopped. HbA1c and weight are measured, not reported, and are less exposed to that bias.
The trial that did test 1.8 mg
PIONEER 4 (NCT02863419, Pratley et al., Lancet 2019) compared semaglutide with liraglutide 1.8 mg — but semaglutide was given as the daily tablet, escalated to 14 mg, not as the Ozempic injection. Over 26 weeks in 711 adults on metformin, HbA1c fell 1.2 points on oral semaglutide and 1.1 on liraglutide 1.8 mg: oral semaglutide was non-inferior, not superior, on the trial's primary estimand. Weight fell 4.4 kg against 3.1 kg. It is the closest thing to a top-dose comparison, and it is not a comparison of the two injections. The tablet's own record is on the Ozempic pill.
The weight-management versions
The same two molecules are sold at higher doses for weight management as Saxenda (liraglutide 3.0 mg daily) and Wegovy (semaglutide 2.4 mg weekly), and those were compared head to head in STEP 8: -16.4% body weight on semaglutide against -6.4% on liraglutide over 68 weeks, in people without diabetes. That trial, and its serious-event figures, are set out on semaglutide vs liraglutide. SUSTAIN 10 is the diabetes-dose answer; STEP 8 is the weight-dose answer. Neither Victoza nor Ozempic is approved for weight loss.
What is not established
- Heart and kidney outcomes head to head. LEADER (liraglutide) and SUSTAIN 6 (semaglutide) each tested a drug against placebo; no trial has compared the two on heart attacks, strokes or deaths, and only semaglutide has a kidney-outcome trial on its label (FLOW).
- Longer than 30 weeks. SUSTAIN 10 reports nothing beyond week 30.
- Children. Victoza is approved from age 10 and Ozempic is not; no trial has compared them in children. The paediatric record for the class is on GLP-1 drugs for teens.
- Cost. Both makers' list and self-pay prices change; generic liraglutide copies of Victoza exist, and there is no US generic semaglutide. Prices are on the Ozempic cost page.
Which of the two, if either, suits a particular person with type 2 diabetes is a decision for their prescriber. Other diabetes-dose comparisons are on Trulicity vs Ozempic and Mounjaro vs Ozempic.
Sources
- ClinicalTrials.gov, NCT03191396 (SUSTAIN 10), posted results: outcome measures and adverse events, read 2026-10-17.
- Capehorn MS et al. "Efficacy and safety of once-weekly semaglutide 1.0 mg vs once-daily liraglutide 1.2 mg as add-on to 1-3 oral antidiabetic drugs in subjects with type 2 diabetes (SUSTAIN 10)." Diabetes Metab 2020;46(2):100-109, PubMed 31539622.
- Pratley R et al. "Oral semaglutide versus subcutaneous liraglutide and placebo in type 2 diabetes (PIONEER 4)." Lancet 2019;394(10192):39-50, PubMed 31186120.
- VICTOZA (liraglutide) injection, Novo Nordisk, label effective 2025-10-14 (set ID 5a9ef4ea-c76a-4d34-a604-27c5b505f5a4); OZEMPIC (semaglutide) injection, Novo Nordisk, label effective 2026-06-01 (set ID adec4fd2-6858-4c99-91d4-531f5f2a2d79); sections 1 and 2, dailymed.nlm.nih.gov, read 2026-10-17.