Liraglutide.
Liraglutide is a long-acting, injectable glucagon-like peptide-1 (GLP-1) receptor agonist, an acylated analog of the human incretin hormone GLP-1.
Liraglutide is a long-acting, injectable glucagon-like peptide-1 (GLP-1) receptor agonist, an acylated analog of the human incretin hormone GLP-1. Liraglutide is fda-approved, and PepCue grades its published evidence S tier (93/100). Also known as Victoza · Saxenda. This is a research reference, not medical or dosing advice.
What it is
Liraglutide is a long-acting, injectable glucagon-like peptide-1 (GLP-1) receptor agonist, an acylated analog of the human incretin hormone GLP-1. It is roughly 97% homologous to native GLP-1, differing by an arginine-for-lysine substitution at position 34 and a C16 palmitic-acid chain attached via a glutamic-acid spacer at lysine 26. That fatty-acid acylation promotes reversible binding to serum albumin and self-association, slowing degradation and renal clearance enough to extend its action to once-daily dosing. It is marketed by Novo Nordisk as Victoza (type 2 diabetes) and Saxenda (chronic weight management), and is now also available as an FDA-approved generic.
How it works
Liraglutide binds and activates the GLP-1 receptor, a Gs-protein-coupled receptor that raises intracellular cyclic AMP. In pancreatic beta cells this potentiates glucose-dependent insulin secretion, meaning insulin release is amplified mainly when blood glucose is elevated; it also suppresses inappropriately high glucagon secretion from alpha cells, which together improve postprandial and fasting glucose. Because the effect is glucose-dependent, GLP-1 agonism carries low intrinsic hypoglycemia risk as monotherapy. Liraglutide additionally slows gastric emptying and acts on hypothalamic appetite circuits to increase satiety and reduce food intake, the basis for its weight-lowering effect.
Mechanism pathways
Activating the GLP-1 receptor to enhance insulin release, slow gastric emptying, and reduce appetite.
Glucagon-like peptide-1 is an incretin hormone released from the gut after a meal. Its receptor is a class B G-protein-coupled receptor found on pancreatic beta cells, on stomach and gut tissue, and on neurons in the hypothalamus and brainstem, including the area postrema. When the receptor is activated, three things happen at once. Beta cells become more responsive to glucose, so insulin secretion rises mainly when blood glucose is already elevated rather than continuously, which is why this class carries a lower intrinsic hypoglycaemia risk than insulin itself. The stomach empties more slowly, flattening the rise in glucose after eating and prolonging the sense of fullness. Central appetite circuits shift toward satiety, reducing the drive to eat between meals. Glucagon secretion is also suppressed when glucose is high. Many compounds target this receptor because native GLP-1 is degraded within minutes by dipeptidyl peptidase-4. Almost every design problem in the class is a half-life problem, and the answers differ. Some analogs attach a fatty-acid chain so the molecule binds albumin and circulates far longer. Others alter the amino acids around the cleavage site so the enzyme cannot act. These structural choices set how often a compound is given and how steeply blood levels rise and fall, which in turn shapes how much nausea a person experiences during the early adjustment period. The class also splits by how many receptors a molecule touches. Pure GLP-1 agonists engage this pathway alone. Dual and triple agonists add GIP, glucagon, or amylin activity on top of it, and combination products pair a GLP-1 agonist with a separate molecule. In every case the GLP-1 arm remains the backbone of the metabolic effect. Of all the pathways described on this site, this one has the strongest and most mature clinical footing. Several GLP-1 receptor agonists are approved medicines for type 2 diabetes, for obesity, or both, and the mechanism has been characterised in humans rather than inferred from animal work. That does not make every molecule in the class equivalent. Some listed here are still investigational, and their receptor activity being well understood says nothing about whether their particular formulation, purity, or long-term profile has been established.
The evidence
Human evidence for liraglutide is extensive and high-quality, not preclinical extrapolation. The LEADER cardiovascular outcomes trial (Marso et al., NEJM 2016; n=9,340 with type 2 diabetes at high cardiovascular risk, median 3.8-year follow-up) found a lower rate of the composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke versus placebo, plus lower cardiovascular and all-cause mortality; its design was prespecified (Marso et al., Am Heart J 2013). For obesity, the 56-week SCALE trial in adults without diabetes (Pi-Sunyer et al., NEJM 2015; n=3,731) showed significantly greater weight loss with liraglutide 3.0 mg plus lifestyle than with placebo plus lifestyle. Liraglutide has also been studied in adolescents with obesity and in prediabetes. The main human gaps now are comparative: newer agents such as semaglutide and tirzepatide produce larger weight reductions in head-to-head and cross-trial comparisons, and liraglutide's once-daily injection is a practical disadvantage.
The evidence, in brief
An earlier once-daily GLP-1 agonist, FDA-approved (Saxenda for weight, Victoza for diabetes) on the strength of the SCALE and LEAD programs. Solid human evidence, generally a smaller average weight effect than the newer weekly agents.
- Pi-Sunyer X et al.: A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management (SCALE)N Engl J Med, 2015 (PMID 26132939)
- Saxenda / Victoza (liraglutide): FDA prescribing informationFDA / DailyMed
Evidence maturity
An evidence-only reading: approval status, human vs preclinical data, mechanism and safety. Popularity never raises it. Research file #037
Approved or strong, consistent human evidence.
FDA-approved for a specific indication: the strongest lane.
Claim receipts
Popular claims about Liraglutide, checked against the state of the evidence. The verdict describes evidence maturity, never an invented study result.
A large randomized 56-week trial in adults with obesity showed significantly greater weight loss than placebo plus lifestyle.
A large prespecified cardiovascular outcomes trial in high-risk type 2 diabetes showed fewer major adverse cardiovascular events than placebo.
Newer agents produce larger weight reductions in comparisons, and daily injection is a practical disadvantage.
Labeling covers pancreatitis, gallbladder disease, acute kidney injury and a boxed warning based on rodent thyroid C-cell findings.
Safety profile
The most common documented adverse effects are gastrointestinal: nausea, vomiting, diarrhea, and constipation, usually dose-related and most pronounced early in treatment. Labeled warnings include acute pancreatitis, acute gallbladder disease (cholelithiasis/cholecystitis), acute kidney injury (often in the setting of dehydration from GI losses), and increased heart rate; in glucose-lowering combinations with insulin or sulfonylureas, hypoglycemia risk rises. Liraglutide carries a boxed warning for thyroid C-cell tumors based on rodent medullary thyroid carcinoma findings, and is contraindicated in people with a personal or family history of medullary thyroid carcinoma or MEN 2; whether this risk translates to humans remains unresolved. Long-term safety in non-medical, non-prescribed "research" use is uncharacterized, and unregulated/compounded sources add contamination and mislabeling risks.
Compound notes
- Liraglutide is a GLP-1 receptor agonist and a predecessor to semaglutide.
- It is FDA-approved (Victoza for type-2 diabetes, Saxenda for weight management).
- It has a shorter half-life (~13 hours) than semaglutide, the basis for once-daily rather than weekly approved formulations.
Same GLP-1 mechanism; liraglutide is shorter-acting (daily) and generally produces somewhat less weight loss in trials than weekly semaglutide.
- Strong evidence for approved uses; common effects are gastrointestinal.
- See the FDA label for warnings and contraindications.
Regulatory status
FDA-approved: as Victoza (2010) for type 2 diabetes in adults and later adolescents, and as Saxenda (2014) for chronic weight management; a generic liraglutide injection has since been approved. It is a legitimately prescribed medication, not a research-only compound, and is not a banned substance under standard anti-doping frameworks the way some hormones are.
Approved by the FDA for at least one indication.
By the numbers
- 01Once-daily injectable GLP-1 receptor agonist; ~97% homologous to native human GLP-1 with a palmitic-acid acylation that extends its half-life
- 02Marketed as Victoza (type 2 diabetes) and Saxenda (weight management) by Novo Nordisk; FDA-approved generic now exists
- 03LEADER (NEJM 2016) demonstrated reduced major adverse cardiovascular events in high-risk type 2 diabetes
- 04SCALE (NEJM 2015) demonstrated significant weight loss versus placebo in adults with obesity without diabetes
- 05Carries a boxed warning for rodent thyroid C-cell tumors; contraindicated with personal/family history of medullary thyroid carcinoma or MEN 2
- 06Largely superseded for weight loss by more potent agents (semaglutide, tirzepatide) in efficacy comparisons
Liraglutide: research formats
Choose the format you are researching to see route-specific notes.
Once-daily SC injection. Both Victoza (diabetes) and Saxenda (weight) use the same titration pattern.
Liraglutide is a once-daily GLP-1 receptor agonist administered by subcutaneous injection via a prefilled multi-dose pen. Saxenda (weight management) and Victoza (type-2 diabetes) use similar but distinct titration schedules.
Sources
Every factual claim above resolves to a real, published source.
- Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes (LEADER)New England Journal of Medicine, 2016, PMID 27295427
- A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management (SCALE)New England Journal of Medicine, 2015, PMID 26132939
- Design of the LEADER trial (liraglutide effect and action in diabetes: cardiovascular outcome results)American Heart Journal, 2013, PMID 24176437
- VICTOZA (liraglutide) injection: FDA prescribing informationFDA/accessdata label, 2023
Cite this page
PepCue. “Liraglutide: the evidence.” PepCue, reviewed June 1, 2026. https://www.pepcue.app/p/liraglutide.
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