Liraglutide

Liraglutide is a 97%-human-sequence GLP-1 receptor agonist — a 31-amino-acid acylated peptide analog of native glucagon-like peptide-1 (GLP-1) — and one of the first long-acting incretin mimetics to reach FDA approval (Victoza for type 2 diabetes in 2010, Saxenda for chronic weight management in 2014). Its design involves a single amino acid substitution at position 34 (lysine → arginine) plus a C16 fatty-acid chain attached to a glutamic acid spacer at position 26, conferring albumin-binding that extends plasma half-life to approximately 13 hours. That pharmacokinetic profile enables once-daily subcutaneous administration — a design that preceded and mechanistically informed the longer-acting, acylation-optimized semaglutide that followed.

Liraglutide exerts its effects through agonism of the GLP-1 receptor (GLP-1R), a Gs-coupled GPCR expressed on pancreatic beta cells, hypothalamic neurons, brainstem neurons, cardiomyocytes, and gastrointestinal enteroendocrine cells. Pancreatic GLP-1R activation drives glucose-dependent insulin secretion — insulin release proportional to ambient glucose concentration, which means GLP-1R agonists cannot produce hypoglycemia by exceeding physiological insulin demand in normoglycemic states, a major advantage over sulfonylureas in research designs studying insulin action. Simultaneously, GLP-1R agonism suppresses glucagon secretion in a glucose-dependent manner, reducing hepatic glucose output during postprandial periods.

Hypothalamic and brainstem GLP-1R populations mediate the central appetite-suppression component of liraglutide's action: GLP-1R agonism in the arcuate nucleus reduces neuropeptide Y (NPY) and agouti-related peptide (AgRP) signaling (orexigenic), while stimulating pro-opiomelanocortin (POMC) and cocaine-and-amphetamine-regulated transcript (CART) neurons (anorexigenic). The area postrema and nucleus tractus solitarius in the brainstem receive vagal afferent signals from the gut and also express GLP-1R, contributing to satiety signaling. Gastric GLP-1R agonism slows gastric emptying, extending postprandial fullness and blunting postprandial glycemic peaks.

In the incretin pharmacology research landscape, liraglutide is a key reference compound for receptor selectivity studies. Unlike tirzepatide (GLP-1R + GIPR dual agonist) or retatrutide (GLP-1R + GIPR + GCGR triple agonist), liraglutide is a mono-selective GLP-1R agonist, making it the standard single-receptor control arm in receptor-contribution experiments. Its FDA approval status also gives it a well-characterized safety and pharmacokinetic database, which researchers use as a benchmark when evaluating newer, unapproved incretin compounds. Peptides.SO tracks 5 liraglutide listings from 4 distinct suppliers, all currently in stock, with per-mg pricing ranging from $19.80 to $304.64 and a median of $45.80/mg.

Potential Research Applications: GLP-1 receptor agonism and incretin signaling pathway characterization Mono-selective GLP-1R reference compound studies benchmarking dual or triple agonists Glucose-dependent insulin secretion and pancreatic beta-cell function models Glucagon suppression and hepatic glucose output studies in type 2 diabetes models Hypothalamic appetite circuit modulation via NPY/AgRP and POMC/CART pathway research Gastric emptying rate and postprandial glycemic kinetics studies Cardiovascular GLP-1R expression and cardioprotective signaling models (LEADER trial context) Comparative pharmacokinetics: once-daily C16 acylation vs once-weekly C18 acylation designs Weight-loss magnitude benchmarking against newer incretin analogs and combination therapies

Marketplace Snapshot (September 2026, Peptides.SO listings data): Tracked listings: 5 from 4 distinct suppliers (5 in stock, all mg-denominated) Median price per mg: $45.80 (range $19.80 – $304.64/mg) Lowest verified per-mg price: $19.80/mg — Peptides World ($99 for 5 mg) Second: $40.00/mg — Genesis Peptides ($40 for 1 mg) Third: $45.80/mg — Iron Mountain Labz ($45.80 for 1 mg) Note: Liraglutide has fewer active research suppliers than semaglutide or retatrutide, likely because its once-daily pharmacokinetics have been superseded in clinical interest by once-weekly agents. Research buyers needing a pure GLP-1R mono-agonist control compound typically find it at 4–5 supplier options, compared with 28+ for retatrutide.

Frequently Asked Questions: Q: How does liraglutide differ from semaglutide in structure and pharmacokinetics? A: Both are acylated GLP-1 analogs, but they differ in acyl chain length and linker design. Liraglutide uses a C16 fatty acid, giving it a ~13-hour half-life suitable for once-daily dosing. Semaglutide uses a C18 fatty acid with a longer, bulkier linker that produces stronger albumin binding and a ~1-week half-life for once-weekly dosing. Structurally, semaglutide also has an additional Aib (alpha-aminoisobutyric acid) substitution at position 8 that protects against DPP-4 cleavage, while liraglutide relies primarily on albumin-binding for plasma stability.

Q: Why is liraglutide a useful reference compound for GLP-1R studies compared with newer dual or triple agonists? A: Because liraglutide is a monoselective GLP-1R agonist, its effects can be attributed exclusively to GLP-1R activation without GIPR or GCGR contributions. In studies comparing incretin receptor contributions to weight loss or glycemic control, liraglutide serves as the GLP-1R-only control arm. Its extensive clinical database (including the LEADER cardiovascular outcomes trial in 9,340 patients) provides a well-characterized pharmacological reference point that preclinical studies can anchor to.

Q: What mechanisms drive liraglutide's appetite suppression? A: Central appetite suppression operates through GLP-1R populations in the hypothalamic arcuate nucleus and in the brainstem (area postrema, nucleus tractus solitarius). Arcuate activation inhibits NPY/AgRP (hunger-promoting) neurons and stimulates POMC/CART (satiety-promoting) neurons, shifting the energy balance set point toward reduced intake. The brainstem component receives vagal afferent satiety signals and amplifies the gut-derived fullness signal. Together these central effects account for most of the weight-loss efficacy seen in liraglutide (SCALE trials: 5.8–8.0% mean weight loss at 1 year, Saxenda 3.0 mg).

Q: How many suppliers offer liraglutide, and what is the typical research price? A: Peptides.SO tracks 5 listings from 4 suppliers. With a median of $45.80/mg and the most competitive option at $19.80/mg (Peptides World, 5 mg vial), liraglutide is priced in the mid-range for research GLP-1 compounds.

Q: Is liraglutide approved for human use? A: Yes. Liraglutide is FDA-approved as Victoza (1.8 mg daily for type 2 diabetes) and Saxenda (3.0 mg daily for chronic weight management). However, research-grade liraglutide listed on this platform is not pharmaceutical-grade and is sold strictly for preclinical and in vitro laboratory use, not for human consumption in any form.

Related Research on Peptides.SO: peptides.so/learn/liraglutide-glp1-research-profile peptides.so/peptide/semaglutide peptides.so/peptide/tirzepatide peptides.so/peptide/retatrutide peptides.so/learn/best-glp-1-research-sources-2026 peptides.so/tools/calculator

Cited Research: Pi-Sunyer X, Astrup A, Fujioka K, et al. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management. N Engl J Med. 2015;373(1):11-22. PubMed PMID: 26132939. Marso SP, Daniels GH, Brown-Frandsen K, et al. Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes (LEADER). N Engl J Med. 2016;375(4):311-322. PubMed PMID: 27295427.

For laboratory research only. Not for human or veterinary use, diagnosis, treatment, cure, or prevention of any disease. THIS PRODUCT IS NOT FOR HUMAN CONSUMPTION.