GLP-1 vs GLP-3
There is no GLP-3. No drug, no receptor by that name in this class, nothing approved or in trials under it. The search is real and rising fast, so it is worth saying plainly what people are usually reaching for.
No clinician has reviewed this page. Label and trial statements are quoted from the FDA label or the trial cited beside them. General guidance is marked as such, and every price carries the date it was verified. That is sourcing, not medical review. What we do and do not check · Who checked the price
Last updated 2026-09-22 — the prices and figures quoted below. Read and dated by Alex Seot.
What is the difference between GLP-1 and GLP-3?
Three things collide. Newer drugs are described as dual and triple agonists — tirzepatide hits two receptors, and retatrutide in trials hits three — so "triple" gets heard as "GLP-3". Marketing copy for supplements and peptides borrows the naming to sound like the prescription drugs. And GLP-1 itself has a sibling, GLP-2, which is a real hormone with a real drug (teduglutide, for short bowel syndrome) and nothing to do with weight.
So somebody who searches GLP-3 is usually asking one of two real questions: what comes after the drug I have heard of, or is the thing being sold to me the same as the thing my doctor prescribes.
The distinction that actually exists
Single agonist: semaglutide acts on the GLP-1 receptor alone. It is sold as Wegovy for weight — 14.9% mean loss in the trial its label cites — and as Ozempic for diabetes.
Dual agonist: tirzepatide acts on GLP-1 and GIP. Sold as Zepbound for weight — 20.9% in its own trial — and as Mounjaro for diabetes.
Triple agonist: retatrutide adds glucagon to those two. It is in trials and is not approved, not prescribable and not for sale — anything sold today under a triple-agonist description is not it.
Oral rather than injected is a separate axis people also conflate with a generation: orforglipron and the Wegovy pill are taken by mouth and are still GLP-1 drugs.
If someone is selling you a GLP-3
Treat the name as the warning. No approved product uses it. halfrx stores 156 FDA warning letters about compounded GLP-1 products, and the pattern in them is claims a real label would not make.
The check is simple and takes a minute: ask which molecule it contains. A real answer is a molecule name — semaglutide, tirzepatide, liraglutide, dulaglutide, orforglipron — and you can look that molecule up. An answer that is a brand, a blend or a generation number is not an answer.
Questions
- Is there a GLP-3 drug?
- No. No drug is approved, marketed or in trials under the name GLP-3. The term appears in supplement marketing and in confusion with triple agonists, which are a real category in trials but are not called that.
- What is GLP-2 then?
- A real hormone, and a real drug class — teduglutide is a GLP-2 analog used in short bowel syndrome. It has nothing to do with weight management and is not an alternative to a GLP-1.
- Is a triple agonist better than a dual?
- Unknown, and not answerable from what is published. Retatrutide is not approved, so there is no label, no verified price and no basis on this site for comparing it with anything.
What this rests on
- FDA prescribing information for ZEPBOUND (tirzepatide)That the dual agonist acts on GIP and GLP-1, and that no approved product is described as a GLP-3.
- FDA prescribing information for WEGOVY (semaglutide)That semaglutide is a single agonist acting on the GLP-1 receptor alone.
- Retatrutide compared with tirzepatide, phase 3 (NCT06662383)That retatrutide is in trials and is not approved, so nothing sold today is it.
- FDA prescribing information for GATTEX (teduglutide)That GLP-2 is a real class with a real drug, used in short bowel syndrome and unrelated to weight.
- FDA: concerns with unapproved GLP-1 drugs used for weight lossWhat the agency says about products sold outside the approved ones.
Every figure above is read from the page of the drug or seller it names, which records where it came from and the date it was verified. Every clinical statement is quoted from one of the labels listed above, never interpreted. Information only, not medical advice.