GLP-3Phase 3
Retatrutide
An investigational triple agonist widely nicknamed "GLP-3" online. There is no GLP-3 hormone or receptor — the name is a consumer shorthand for a molecule that hits three receptors at once.
Half-life ~6 daysRead →
35 PEPTIDES · 12 CLASSES · 44 SOURCES
GLPWikiThe encyclopedia of peptides
Incretins and the triple agonists people call GLP-3, plus repair peptides, growth-hormone secretagogues, melanocortins and the rest of the field. Every entry states the mechanism, the receptor targets, the evidence, and where it came from.
GLPWiki is an independent, citation-first educational reference. It sells nothing, links to no suppliers, carries no sponsored entries, and publishes no doses or protocols. It explains what a compound is and what has been measured — it is not medical advice.
DATASHEET · RETATRUTIDE
- Also called
- GLP-3
- Receptors
- GLP-1 + GIP + glucagon
- Half-life
- ~6 days
- Status
- Phase 3
GLP-3 is not a hormone or a receptor. It is a nickname for retatrutide, an investigational Eli Lilly triple agonist. Not approved by any regulator.
START HERE
What GLP-1 actually is
The incretin hormone behind semaglutide and liraglutide — receptor, mechanism, clinical landscape.
GLP-2, the intestinal sibling
Same precursor protein, entirely different receptor and job: growth and repair of the gut lining.
There is no GLP-3 hormone
Why the nickname attached itself to retatrutide, and what a triple agonist really does.
TOOLS
Open calculatorsPeptide calculators
Reconstitution maths without the guesswork: concentration, volume to draw, syringe units and doses per vial. Educational arithmetic only — not dosing guidance.
LONG FORM
All 27 guides →Guides
LITERACY
Oral semaglutide vs injectable: Rybelsus, Wegovy tablets, and injection literacy
Semaglutide is one active ingredient that appears in multiple FDA-approved finished products with different routes — oral tablets co-formulated with the absorption enhancer SNAC, and subcutaneous injections without that tablet technology. This literacy guide is distinct from the general oral-peptides-absorption explainer: it maps finished-product route differences, SNAC versus injection framing, product-specific labeled uses (including oral Wegovy tablets when labeled), fasting/admin CONCEPT literacy without doses, and how approved oral peptide-formulated products differ from research "oral peptide" marketing claims.
14 MIN READ
LITERACY
GLP-1 labeled indication expansions: CV, CKD, MASH, and OSA literacy
Beyond classic glycemic-control and weight-management shorthand, some FDA-approved GLP-1 and related incretin products carry additional labeled uses — cardiovascular risk reduction, chronic kidney disease–related language, MASH under accelerated approval, and obstructive sleep apnea. This literacy companion to Day 19's medications-by-indication guide teaches that those expansions attach to specific finished-product labels, may use accelerated-approval language, change over time, and must be verified on Drugs@FDA — never assumed from molecule name, another brand, or headlines.
14 MIN READ
LITERACY
FDA-approved GLP-1 medicines by indication: diabetes, weight, and beyond
The same active ingredient can appear under different brand names with different labeled indications. This literacy companion to the /medications hub explains how to read Indications & Usage and Limitations of Use on Prescribing Information via Drugs@FDA — without doses, schedules, or product recommendations.
13 MIN READ
REFERENCE LIBRARY
View all 35 →Featured peptides
GLP-1Approved
Semaglutide
A once-weekly GLP-1 receptor agonist and the most widely prescribed drug in the class. Approved for type 2 diabetes, chronic weight management and cardiovascular risk reduction.
Half-life ~7 daysRead →
DUAL AGONISTApproved
Tirzepatide
The first approved dual incretin agonist, activating both the GIP and GLP-1 receptors. Approved for type 2 diabetes, chronic weight management and obstructive sleep apnoea in obesity.
Half-life ~5 daysRead →
LONG FORM
All articles →Deep dives
DEEP DIVE
Retatrutide, the peptide the internet calls GLP-3
Why a triple agonist picked up a nickname that does not describe a real hormone — and what its trial data actually show.
EVIDENCE CHECK
BPC-157: separating the claims from the evidence
The most discussed repair peptide on the internet has an enormous animal literature and almost no human trials. Here is the honest state of play.
COMPARISON
GH secretagogues compared: sermorelin, ipamorelin, CJC-1295, tesamorelin
Four peptides that all raise growth hormone, by three different mechanisms, with wildly different levels of evidence.
COMMON QUESTIONS
What people ask first
- Is GLP-3 a real hormone?
- No. There is no GLP-3 hormone or receptor. It is an informal nickname used online for retatrutide, an investigational triple agonist that activates the GLP-1, GIP and glucagon receptors at once.
- What is the difference between GLP-1 and GLP-2?
- Both are cleaved from the same proglucagon precursor, but they act on different receptors. GLP-1 drives insulin secretion and satiety; GLP-2 drives intestinal growth and absorption and is used in short bowel syndrome, not weight management.
- Why do dual and triple agonists produce more weight loss?
- Adding GIP and glucagon receptor activity recruits pathways GLP-1 alone does not reach — GIP appears to improve tolerability and adipose handling, while glucagon raises energy expenditure and mobilises hepatic fat.
- Where does the information here come from?
- Every entry cites primary sources: peer-reviewed trial publications and trial registry records. Figures are trial means under protocol conditions, not predictions for any individual.