GLP-1 vs glp 3
You are deciding between two options.
Reference and calculator, not medical advice. This page explains how something works; it does not tell you what to take. Last reviewed August 2026.
There is no GLP-3. Not a newer drug, not one in trials, not something available elsewhere — the hormone itself does not exist. If you have seen it referenced, it was either a mistake or someone marketing a product using a name that sounds like the next step in a series.
What proglucagon actually produces
GLP-1 and GLP-2 are both cut from the same precursor protein. This is the complete list of what that protein yields.
- GlucagonRaises blood glucose. The hormone the whole family is named after.
- GLP-1Glucagon-like peptide-1. Regulates appetite and caloric intake; the target of every medication on this site.
- GLP-2Glucagon-like peptide-2. Acts on the intestine — increases intestinal blood flow and inhibits gastric acid secretion. Nothing to do with appetite.
- OxyntomodulinAlso cleaved from proglucagon. No approved analogue on the US market.
There is no GLP-3. The numbering stops at two because only two glucagon-like peptides are produced. No such hormone appears in the physiology literature, and a search of the FDA drug label database returns zero results for it.
The reason the numbering stops at two is that it was never a ranking. Proglucagon is a precursor protein that gets cut into pieces, and two of those pieces resemble glucagon closely enough to be called glucagon-like peptides. They were numbered by their position on the precursor. There is no third one to discover, because there is no third fragment to name.
What people usually want when they search this is one of two real things: either the difference between GLP-1 and GLP-2, or what tirzepatide adds on top of GLP-1 — which is GIP, a completely separate incretin hormone rather than a higher-numbered GLP.
What GIP actually is
Glucose-dependent insulinotropic polypeptide — a separate incretin hormone, not part of the proglucagon family at all.
- FDA-approved medication
- Yes
- Approved for
- No GIP-only medication is marketed. GIP is targeted alongside GLP-1 by tirzepatide.
- Example
- Tirzepatide (Zepbound, Mounjaro) is a dual GIP and GLP-1 receptor agonist
- Difference that matters
- Not an alternative to GLP-1 but a second target hit at the same time. The Zepbound label describes tirzepatide as "a GIP receptor and GLP-1 receptor agonist".
This page describes what each thing is and what it is approved for. It does not compare how well they work, because that is a question for a prescriber with your history in front of them.
Common questions
- Is a GLP-3 drug in development?
- A drug cannot be developed against a receptor that does not exist. What is genuinely in development are multi-agonists targeting combinations of real hormones — GLP-1, GIP and glucagon among them. None of those is called GLP-3.
- Someone is selling me a "GLP-3" product. What is it?
- It is not a recognised drug class, so the name tells you nothing about what is in the vial. That alone is a reason to be careful. Ask what the actual active ingredient is and whether it appears in any FDA-approved product.
- So what is the strongest option available?
- Not a question this site answers, and not one that maps onto a numbered series anyway. Products differ in active ingredient, targets and labelled maximum dose; how any of that plays out for a person is a prescriber conversation.
Sources and last review
This page is general reference rather than a dosing table, so it quotes no figures from a label. Nothing here is reviewed by a clinician, and this site does not employ one — which is exactly why what I do publish stays traceable to its source.
- This page carries no product-specific dosing figures. The labels behind everything on this site are listed on the sources page, and the originals live on DailyMed.
Transcribed from the labels above and checked by me — Gavin, who builds this site, takes a GLP-1, and is not a clinician. Last reviewed August 2026. Found an error? [email protected] — I treat corrections as bugs. How this site is built and funded.
Citing this page
The figures here are transcribed from FDA-approved labels and each links to its source. If you are writing about this, quote the label rather than this site where you can — and if this page saved you the transcription, a link is appreciated.
Gavin. "GLP-1 vs glp 3." GLP1Meter, reviewed August 2026. https://glp1meter.com/compare/glp-1-vs-glp-3/<a href="https://glp1meter.com/compare/glp-1-vs-glp-3/">GLP-1 vs glp 3</a> — GLP1Meter, reviewed August 2026Gavin. (2026). GLP-1 vs glp 3. GLP1Meter. Retrieved from https://glp1meter.com/compare/glp-1-vs-glp-3/
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