Liraglutide reached the market years before the weekly GLP-1 drugs that now dominate headlines. The FDA cleared it for type 2 diabetes as Victoza in January 2010, then approved the higher 3.0 mg dose for chronic weight management as Saxenda in December 2014 (FDA/Novo Nordisk announcement, 2014). Both products are approved drugs administered by daily subcutaneous injection. This article reports the published trial record. It is not medical or dosing advice.
The SCALE weight-management program
SCALE (Satiety and Clinical Adiposity — Liraglutide Evidence) was the phase 3 program behind the obesity indication. The pivotal trial, SCALE Obesity and Prediabetes, was a 56-week, double-blind, placebo-controlled study in 3,731 adults without diabetes who had a BMI of at least 30, or at least 27 with a weight-related condition (Pi-Sunyer et al., NEJM 2015). Participants were randomized 2:1 to liraglutide 3.0 mg or placebo, both on top of a reduced-calorie diet and increased activity.
The headline numbers from that trial:
| Endpoint | Liraglutide 3.0 mg | Placebo |
|---|---|---|
| Mean weight change | -8.0% (-8.4 kg) | -2.6% (-2.8 kg) |
| Lost ≥5% of body weight | 63.2% | 27.1% |
| Lost >10% of body weight | 33.1% | 10.6% |
All three comparisons were reported at p<0.001. The trial was funded by Novo Nordisk, the manufacturer, which is standard for registration studies but worth keeping in mind when reading the results.
A separate arm followed people with prediabetes for three years. Reported in The Lancet, liraglutide delayed the onset of type 2 diabetes compared with placebo over 160 weeks (le Roux et al., Lancet 2017).
Safety signals from SCALE
Gastrointestinal effects dominated the adverse-event profile. Nausea was reported in roughly 40% of the liraglutide group versus about 15% on placebo, with higher rates of vomiting and diarrhea as well. These were mostly transient and tied to dose escalation, but they drove a meaningful share of dropouts. Gallbladder disease showed up more often on liraglutide, consistent with rapid weight loss. Acute pancreatitis was rare but occurred slightly more in the treatment group. The label carries a boxed warning about thyroid C-cell tumors, based on rodent data; whether this translates to humans is not established.
LEADER: the cardiovascular outcomes trial
LEADER tested whether liraglutide, at the 1.8 mg diabetes dose, was safe and beneficial for the heart. It enrolled 9,340 adults with type 2 diabetes at high cardiovascular risk — either age 50 or older with established cardiovascular, cerebrovascular, peripheral arterial, renal, or heart-failure disease, or age 60 or older with at least one risk factor (Marso et al., NEJM 2016). Patients received liraglutide or placebo on top of standard care, with a median follow-up of 3.8 years.
The primary outcome was a three-part composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke (MACE):
- MACE occurred in 13.0% of the liraglutide group (608 of 4,668) versus 14.9% on placebo (694 of 4,672)
- Hazard ratio 0.87 (95% CI 0.78–0.97), p<0.001 for noninferiority and p=0.01 for superiority
- Cardiovascular death: HR 0.78 (95% CI 0.66–0.93), p=0.007
- Death from any cause: HR 0.85 (95% CI 0.74–0.97), p=0.02
The absolute difference in the primary endpoint was modest — under two percentage points over almost four years — but the reduction in cardiovascular and all-cause death is what moved guidelines. LEADER was the basis for Victoza later carrying an FDA indication to reduce the risk of major cardiovascular events in adults with type 2 diabetes and established cardiovascular disease.
LEADER does not speak to people without diabetes or to the 3.0 mg obesity dose. The population was specifically high-risk diabetic patients, so the findings shouldn't be read as a general cardiovascular claim for everyone using a GLP-1.
How daily liraglutide compares with the weekly agents
Liraglutide is the older, daily molecule. Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) are dosed once weekly and, in their own trials, produced larger weight reductions. The cleanest head-to-head in diabetes is SUSTAIN 10, an open-label trial of 577 patients randomized to weekly semaglutide 1.0 mg or daily liraglutide 1.2 mg (Capehorn et al., Diabetes Metab 2020). Semaglutide cut HbA1c by 1.7% versus 1.0% for liraglutide, and reduced body weight by 5.8 kg versus 1.9 kg.
A few caveats on that comparison. SUSTAIN 10 used liraglutide's 1.2 mg diabetes dose, not the 1.8 mg dose from LEADER or the 3.0 mg obesity dose from SCALE, so it isn't a maximal-dose matchup. Cross-trial comparisons of the obesity doses (Saxenda's 3.0 mg versus Wegovy's 2.4 mg semaglutide or tirzepatide) are not randomized against each other and should be read loosely. What the data consistently show is a gradient: the weekly agents tend to deliver more weight loss, while liraglutide carries the longest real-world track record and a confirmed cardiovascular outcomes trial in diabetes.
One practical note for anyone reading vendor or testing sites: liraglutide, semaglutide, and tirzepatide sold through compounding or research-chemical channels are not the FDA-approved branded products and may be labeled research-use-only or not for human consumption. Third-party analytical labs such as Janoshik publish identity and purity testing on submitted samples, but a certificate of analysis describes one tested vial, not the clinical evidence base or any approval status. The trial figures above apply to the approved drugs studied at the doses described.
Everything here is a summary of published evidence with attribution. It is not a recommendation, and it is not medical advice. Decisions about any of these drugs belong with a licensed clinician.