Overview
Liraglutide (trade names Victoza, type 2 diabetes, and Saxenda, weight management; developer Novo Nordisk) is a synthetic analogue of glucagon-like peptide-1 (GLP-1) engineered for once-daily subcutaneous administration. The molecule is 97% homologous to endogenous GLP-1(7-37): a single Lys34→Arg substitution plus a palmitic (C16) fatty-acid chain attached via a γ-glutamate linker at Lys26 [1]. This acylation enables reversible binding to plasma albumin, which slows renal clearance and proteolytic degradation by dipeptidyl peptidase-4 (DPP-4), extending the half-life to roughly 13 hours after subcutaneous injection, versus a few minutes for native GLP-1 [1][2]. Longeva does not sell the Victoza/Saxenda brands; liraglutide is supplied strictly as a research reagent with a batch-specific certificate of analysis (COA).
Pharmacology and mechanism of action
As a GLP-1 receptor (GLP-1R, a class B GPCR) agonist, liraglutide binds the receptor on pancreatic β-cells, stimulating glucose-dependent insulin secretion via increased intracellular cAMP; insulin release subsides as glycaemia approaches normal, limiting the hypoglycaemia risk seen with glucose-independent insulin secretagogues [1]. In parallel, glucose-dependent glucagon secretion from α-cells is suppressed and gastric emptying is slowed. GLP-1R is also expressed in hypothalamic nuclei involved in central satiety regulation, this pathway underlies the weight-reduction effect, more pronounced at the higher (up to 3 mg/day) doses used in the weight-management program [3][5].
Clinical data
The first-in-human study confirmed the predicted single-dose pharmacokinetics and acceptable tolerability in healthy volunteers [2]. In a head-to-head comparison with twice-daily exenatide (LEAD-6), once-daily liraglutide produced significantly greater HbA1c reduction over 26 weeks in patients with type 2 diabetes, with predominantly gastrointestinal adverse events in both arms [4]. In a non-diabetic population, a randomized placebo-controlled trial of doses from 1.2 to 3 mg/day showed dose-dependent weight loss over 20 weeks, supporting further development of the higher 3 mg dose [3]. The pivotal weight-management trial (56 weeks, 3 mg/day, participants without diabetes) confirmed clinically meaningful weight loss versus placebo on top of diet and physical activity [5].
Research status and handling
In a research context, liraglutide is supplied as a lyophilized powder; purity and identity for a specific batch are confirmed by its COA, not by the label. Longeva's materials are intended strictly for laboratory research use, not for human consumption, and do not constitute medical, therapeutic, or dosing advice. All doses and results cited above describe the design of published clinical studies and must not be read as instructions.