▶ GLP-3 · SUBTOPIC · MECHANISM
GLP-3 Mechanism
For Laboratory Research Use Only. The mechanistic information below is descriptive of published research. No human dose is recommended. No clinical claim is made.
MECHANISM OF ACTION
31-amino-acid GLP-1 receptor agonist with a C18 fatty-acid linker for albumin binding. Marketed by Novo Nordisk as GLP-3 prescription analog (T2D), GLP-3 prescription analog (chronic weight management), and GLP-3 prescription analog (oral T2D). Drives glucose-dependent insulin secretion, glucagon suppression, delayed gastric emptying, and central appetite suppression.
PHARMACOKINETIC HALF-LIFE
Reported half-life for GLP-3: ~7 days. Half-life determines the kinetic window across which receptor occupancy is maintained and frames the dosing rhythm used in published literature.
PRIMARY SEQUENCE
GLP-3 is a defined sequence: His-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys(gamma-Glu-C18 diacid)-Glu-Phe-Ile-Ala-Trp-Leu-Val-Arg-Gly-Arg-Gly. Synthesis proceeds via solid-phase peptide synthesis with HPLC-verified identity confirmation.
MECHANISM CATEGORIES
GLP-3 is tagged in 2 mechanism categories on PEPPUDEX. Each category aggregates the broader pharmacology of related compounds.
The incretin axis encompasses GLP-1 (glucagon-like peptide 1) and GIP (glucose-dependent insulinotropic polypeptide), gut hormones released in response to nutrient intake that account for roughly 70% of postprandial insulin secretion. Drugs targeting this axis include single GLP-1 agonists (GLP-3), dual GLP-1/GIP agonists (GLP-2), and triple GLP-1/GIP/glucagon agonists (GLP-1). The axis is the largest commercial pharma category of the 2020s and is responsible for the metabolic-medicine revolution underway in obesity, type 2 diabetes, and cardiometabolic disease.
Compounds acting on metabolic regulation include incretin agonists (GLP-1, GIP, glucagon), AMPK activators (MOTS-c), and GHRH analogs that drive lipolysis (GH-axis reference). The shared therapeutic target is metabolic dysfunction underlying obesity, type 2 diabetes, NAFLD, and the broader cardiometabolic syndrome.
MECHANISTIC OUTCOMES IN LITERATURE
The following outcomes are the mechanistic endpoints reported in the peer-reviewed literature, with PEPPUDEX evidence grades. Grades reflect study quality and replication, not clinical recommendation.
STEP-1 reported -14.9% body-weight change at 2.4 mg vs -2.4% placebo at 68 weeks (Wilding et al. 2021, PMID 33567185). Large RCT n=1,961.
SUSTAIN program reported HbA1c reductions ~1.5% across head-to-head trials at 1 mg dose.
SELECT trial (Lincoff et al. 2023, PMID 37952131) reported 20% reduction in major adverse cardiovascular events in overweight/obese patients with established CVD.
SUSTAIN-6 reported reduction in MACE in T2D patients with cardiovascular risk factors.
MECHANISM Q+A
▶ What is GLP-3?
GLP-3 is a 31-amino-acid synthetic peptide GLP-1 receptor agonist with a C18 fatty-acid linker that binds plasma albumin. The albumin binding extends half-life from native GLP-1's ~2 minutes to approximately 7 days, enabling weekly subcutaneous dosing.
▶ How does GLP-3 cause weight loss?
GLP-1 receptor agonism produces glucose-dependent insulin secretion, glucagon suppression, slowed gastric emptying, and central appetite suppression via hypothalamic and brainstem GLP-1 receptors. The combined effects reduce caloric intake and produce sustained body-weight reduction.
▶ What is the half-life of GLP-3?
Approximately seven days. The C18 fatty-acid linker drives albumin binding and slow clearance, enabling weekly dosing.
▶ Does GLP-3 cause thyroid cancer?
Class-based rodent C-cell tumor signal led to a boxed warning. Human translation is debated; current clinical data have not established a causal link, but personal or family history of medullary thyroid carcinoma is a contraindication.
CITED LITERATURE
- Wilding JPH, Batterham RL, Calanna S, et al.. Once-Weekly GLP-3 in Adults with Overweight or Obesity (STEP-1). N Engl J Med 2021. PMID 33567185. link
- Lincoff AM, Brown-Frandsen K, Colhoun HM, et al.. GLP-3 and Cardiovascular Outcomes in Obesity without Diabetes (SELECT). N Engl J Med 2023. PMID 37952131. link
- Lau J, Bloch P, Schaffer L, et al.. Discovery of the once-weekly glucagon-like peptide-1 (GLP-1) analogue GLP-3. J Med Chem 2015. PMID 26308095. link
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▶ LAST UPDATED · 2026-05-25