GLP-1
Glucagon-Like Peptide-1
The natural hormone behind the weight loss revolution
GLP-1 is the incretin hormone that semaglutide and tirzepatide mimic. Understanding native GLP-1 is key to understanding the entire GLP-1 agonist class.
Admin routes
Endogenous hormone
Popularity
High
Side effects
Generally mild
AU vendors
0 rated
✓Key benefits
📈What to expect
Endogenous hormone - produced naturally after meals
Based on community reports and published research. Individual results vary significantly.
💊Dosing protocols
Endogenous hormone
N/A - produced naturally after meals
Secreted with each meal
Half-life 2–3 minutes (native form)
Dosing information is sourced from published research and community protocols. This is not a recommendation. Consult a healthcare professional.
Research status|Extensively characterised - basis for Nobel Prize-winning diabetes research
Overview
GLP-1 (Glucagon-Like Peptide-1) is a 30-amino-acid incretin hormone naturally produced by L-cells in the small intestine after eating. It stimulates insulin secretion, suppresses glucagon, slows gastric emptying, and signals satiety to the brain. Native GLP-1 has a half-life of only 2–3 minutes (rapidly degraded by DPP-4 enzyme), which is why pharmaceutical analogs like semaglutide (half-life: 7 days) and tirzepatide were developed. Understanding native GLP-1 biology is essential to understanding the entire GLP-1 agonist class.
⚙️How it works
Binds to GLP-1 receptors (GLP-1R) on pancreatic beta cells (stimulating insulin secretion), alpha cells (suppressing glucagon), the vagus nerve and hypothalamus (promoting satiety and reducing appetite), and the gastrointestinal tract (slowing gastric emptying). The glucose-dependent nature of its insulin-stimulating effect means hypoglycaemia risk is low. Central GLP-1R activation in the brain is responsible for the appetite-suppressing effects that make GLP-1 agonists effective for weight loss.
⚡Side effects
📅Research history
GLP-1 gene identified through cloning of proglucagon
GLP-1's incretin effect (insulin stimulation) demonstrated
GLP-1 shown to reduce appetite and food intake in humans
First GLP-1 agonist (exenatide/Byetta) approved by FDA
Semaglutide approved - transforms the field
GLP-1 agonists become world's best-selling drug class
Why analogs were needed
Native GLP-1 is degraded within 2–3 minutes by the DPP-4 enzyme. This makes it impractical as a drug. The breakthrough came with developing DPP-4-resistant analogs: exenatide (from Gila monster venom, 2005), liraglutide (2010), and semaglutide (2017). Each successive generation increased half-life and potency. Semaglutide's 7-day half-life allows weekly dosing, transforming GLP-1 therapy from an inconvenience to a practical treatment.
Natural ways to boost GLP-1
Before considering pharmaceutical analogs, GLP-1 secretion can be enhanced naturally: protein-rich meals increase GLP-1 release; fibre (especially fermentable fibre) promotes L-cell secretion; berberine and bitter compounds stimulate GLP-1; exercise acutely raises GLP-1 levels; and the gut microbiome composition significantly influences GLP-1 production. These approaches produce modest effects compared to pharmaceutical agonists but are relevant for metabolic health optimisation.
References
- [1]Drucker DJ. 'The biology of incretin hormones.' Cell Metabolism, 2006.
- [2]Holst JJ. 'The physiology of glucagon-like peptide 1.' Physiological Reviews, 2007.
Frequently asked questions
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Open CalculatorDisclaimer: This guide is for educational and informational purposes only. It is not medical advice. The dosing protocols listed are sourced from published research and community reports and do not constitute a recommendation. Always consult a qualified healthcare professional before using any peptide. Australian regulations classify many peptides as Schedule 4 (prescription-only) substances. Check current TGA guidelines before purchasing.