Educational reference, not medical advice. This page summarizes information from published research and regulatory filings for educational purposes. It is not a recommendation to use any compound and should not replace guidance from a licensed healthcare provider. Most peptides discussed here are not approved for the uses described.
What it is
Liraglutide is a synthetic analog of human glucagon-like peptide-1 (GLP-1) developed by Novo Nordisk. Native GLP-1 has a half-life of roughly two minutes because the enzyme DPP-4 rapidly degrades it. Liraglutide was engineered with two modifications — a single amino acid substitution at position 34 and a C16 fatty acid (palmitic acid) side chain attached via a glutamic acid spacer — that together make the molecule bind reversibly to albumin and resist DPP-4 cleavage. The result is a circulating half-life of about 13 hours, supporting once-daily subcutaneous dosing.
It is the same active molecule under two brand names: Victoza (lower-dose pens, type 2 diabetes) and Saxenda (higher-dose pens, chronic weight management).
History
Novo Nordisk filed the original patents in the late 1990s and published the development chemistry in 2000. Liraglutide became the second GLP-1 agonist on the market after exenatide (Byetta), but it was the first GLP-1 agonist with a 24-hour duration of action.
- January 2010 — FDA approves Victoza for adults with type 2 diabetes.
- December 2014 — FDA approves Saxenda for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity.
- 2016 — LEADER trial publishes; liraglutide reduced the primary composite cardiovascular outcome by 13% versus placebo in patients with type 2 diabetes (hazard ratio 0.87).
- 2017 — FDA adds cardiovascular risk reduction indication to Victoza.
- 2020 — FDA approves Saxenda for adolescents aged 12 and older with obesity.
- 2024 — First generic liraglutide approved by the FDA, broadening access.
In the pivotal SCALE Obesity and Prediabetes trial, the 3.0 mg liraglutide dose produced a mean weight loss of 8.0% from baseline at 56 weeks versus 2.6% on placebo.
Regulatory status
Liraglutide is approved in the United States, the European Union, the United Kingdom, Canada, Japan, and most other major markets. Both the diabetes (1.8 mg/day maximum) and weight-management (3.0 mg/day maximum) indications are well-established. With generic liraglutide now available, compounding pressure has decreased relative to semaglutide and tirzepatide.
Mechanism
Liraglutide activates the GLP-1 receptor, which is expressed in pancreatic islet cells, the gastrointestinal tract, and several regions of the central nervous system. The published mechanism papers describe four main effects:
- Glucose-dependent insulin secretion from pancreatic beta cells, with low hypoglycemia risk because insulin release falls off as glucose normalizes.
- Suppression of glucagon secretion, reducing hepatic glucose output.
- Slowed gastric emptying, prolonging meal-related satiety.
- Central appetite regulation through receptors in the hypothalamus and brainstem.
The cardiovascular benefit demonstrated in the LEADER trial is thought to reflect a combination of weight loss, blood pressure reduction, and possibly direct vascular effects.
Half-life and dosing intervals
The published terminal half-life is approximately 13 hours, and steady-state plasma concentrations are reached within 3 days of consistent dosing. Both labels require gradual dose escalation:
- Victoza (T2D): 0.6 mg subcutaneously once daily for one week → 1.2 mg daily → may increase to 1.8 mg daily if additional glycemic control is needed.
- Saxenda (weight management): 0.6 mg subcutaneously once daily for one week → escalate by 0.6 mg weekly through 1.2, 1.8, 2.4, and 3.0 mg → 3.0 mg daily maintenance.
The 0.6 mg starting dose is a tolerability dose, not a therapeutic dose. The labels state escalation should pause if gastrointestinal side effects are intolerable.
Reconstitution example
Branded liraglutide ships in multi-dose pre-filled pens that do not require reconstitution; the dose is selected via a dial. Compounded liraglutide sold for research use is typically lyophilized in 10 mg or 20 mg vials.
A 10 mg vial reconstituted with 2 mL of bacteriostatic water yields 5 mg/mL. On a 1 mL U-100 insulin syringe, 12 units (0.12 mL) contains 0.6 mg — the starting dose used in both labels. Vial's calculator handles the unit-to-mg conversion automatically.
What to know
- Common side effects in trials: nausea, vomiting, diarrhea, constipation, headache. Most are mild-to-moderate and concentrated during escalation.
- Boxed warning. FDA labels carry a boxed warning regarding risk of thyroid C-cell tumors based on rodent studies; contraindicated in patients with personal or family history of medullary thyroid carcinoma or MEN 2.
- Pancreatitis. Acute pancreatitis has been reported in post-marketing data; discontinue if suspected.
- Daily injection. Unlike semaglutide and tirzepatide, liraglutide requires a daily injection, which affects adherence.
- Storage. Pre-filled pens: refrigerate before first use; after first use store at room temperature or refrigerated for up to 30 days. Compounded lyophilized: refrigerate after reconstitution.
Sources
- 1.Marso SP et al. (2016). Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes (LEADER). New England Journal of Medicine.
- 2.Pi-Sunyer X et al. (2015). A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management (SCALE Obesity and Prediabetes). New England Journal of Medicine.
- 3.Davies MJ et al. (2015). Efficacy of Liraglutide for Weight Loss Among Patients With Type 2 Diabetes: The SCALE Diabetes Randomized Clinical Trial. JAMA.
- 4.FDA Prescribing Information — Saxenda (liraglutide) injection.
- 5.FDA Prescribing Information — Victoza (liraglutide) injection.