Skip to content

GLP-1 & Metabolic Peptides Research Hub

Overview

GLP-1 receptor agonists and metabolic peptides represent the most commercially and scientifically significant category in peptide research. From glucose homeostasis to body weight regulation, these peptides target evolutionarily conserved metabolic pathways with increasing precision.

HK Peptides Worldwide supplies 7 GLP-1 and metabolic research peptides across 20+ SKU configurations — manufacturer-direct, HPLC-verified, with batch-specific COA documentation.

The Incretin System

The incretin effect describes the observation that oral glucose elicits a greater insulin response than intravenous glucose. Two key incretin hormones mediate this effect:

Hormone Source Receptor Primary Actions
GLP-1 (Glucagon-Like Peptide-1) Intestinal L-cells GLP-1R Insulin secretion (glucose-dependent), glucagon suppression, gastric emptying delay, satiety
GIP (Glucose-dependent Insulinotropic Peptide) Intestinal K-cells GIPR Insulin secretion, lipid metabolism, bone formation

Native GLP-1 has a half-life of ~2 minutes due to rapid DPP-4 cleavage. All therapeutic-grade GLP-1 analogs require DPP-4 resistance engineering to achieve meaningful exposure duration.

Product Comparison: GLP-1 Receptor Agonists

Parameter Semaglutide Tirzepatide Retatrutide
CAS 910463-68-2 2023788-19-2 2381089-83-2
Receptors GLP-1R GIPR + GLP-1R GIPR + GLP-1R + GCGR
MW ~4,113.6 Da ~4,813.5 Da ~4,845.5 Da
DPP-4 Resistance Aib⁸ substitution Engineered Engineered
Half-Life Extension C18 fatty diacid (albumin binding) C20 fatty diacid C20 fatty diacid
Synthesis Complexity High Very High Complex
Research Stage Most studied Advanced Phase 2/3

Semaglutide

The foundation GLP-1R agonist. Two key structural modifications — Aib⁸ for DPP-4 protection and C18 fatty diacid at Lys²⁶ for albumin binding — produce a ~7-day half-life. The most extensively characterized peptide in the GLP-1 category.

Full Specification →

Tirzepatide

The first dual incretin agonist to demonstrate superiority over GLP-1 monotherapy. Co-activating GIPR and GLP-1R produces enhanced metabolic effects including greater weight reduction and improved glycemic control.

Full Specification →

Retatrutide

Triple receptor agonism (GIPR + GLP-1R + GCGR) represents the frontier of metabolic peptide research. GCGR activation increases energy expenditure through hepatic mechanisms, adding a thermogenic dimension to incretin-based therapy.

Full Specification →

Complementary Metabolic Peptides

Cagrilintide

Long-acting amylin analog. Amylin is co-secreted with insulin from pancreatic β-cells and contributes to satiety signaling and gastric emptying. Cagrilintide + Semaglutide combination (CagriSema) is under investigation for enhanced weight management.

AOD-9604

Synthetic hGH C-terminal fragment (amino acids 177-191). Retains the lipolytic domain of growth hormone without GHR binding — meaning fat mobilization occurs without IGF-1 elevation, insulin resistance, or growth-promoting activity.

MOTS-c

Mitochondrial-derived peptide encoded within the 12S rRNA region. Regulates metabolic flexibility and insulin sensitivity through AMPK activation and folate cycle modulation. Represents an emerging class of mitochondrial signaling peptides.

Tesamorelin

GHRH analog that stimulates pituitary GH secretion. Used in research contexts involving visceral adipose tissue reduction and body composition studies.

Research Framework

Key Assays for Metabolic Peptide Research

Assay Target Readout
GLP-1R cAMP assay Receptor activation EC₅₀, efficacy
Glucose tolerance test (GTT) In vivo glucose handling Blood glucose AUC
Food intake measurement Appetite/satiety Cumulative food intake
Body composition (DEXA/MRI) Fat/lean mass % change
Gastric emptying assay GI motility Time to 50% emptying
Energy expenditure Metabolic rate O₂ consumption, CO₂ production

Quality Specifications

All metabolic peptides from HK Peptides Worldwide meet:

  • ≥99% HPLC purity — C18 reverse-phase, 214/220 nm
  • ESI-MS molecular weight confirmation — ±1.0 Da
  • Linker integrity verification — HPLC-ELSD or LC-MS/MS for fatty acid-conjugated peptides
  • Batch-specific COA — included with every order