Retatrutide vs Ozempic

The short answer

Ozempic is a brand name for semaglutide, a licensed prescription medicine. Retatrutide is an investigational compound with no marketing authorisation. Semaglutide acts at a single receptor; retatrutide is described as acting at three.

Receptor targets

Semaglutide was the first of this group to become widely known, which is why it tends to be the comparison people reach for. It is also the simplest of the three mechanisms — a single receptor — where tirzepatide adds GIP and retatrutide adds both GIP and glucagon.

Three compounds, one family

Set side by side, the progression is easier to follow than any one comparison:

• Semaglutide — GLP-1. Licensed medicine.
• Tirzepatide — GIP + GLP-1. Licensed medicine.
• Retatrutide — GIP + GLP-1 + glucagon. Investigational.

Adding a receptor target is not the same as improving on the previous compound, and the published evidence base shortens considerably as you move down that list. See retatrutide vs Mounjaro for the tirzepatide comparison in full.

What is actually published

Retatrutide's human data is at phase 2 (PMID 37366315), where semaglutide and tirzepatide have completed the programmes required for authorisation. That difference in evidence — not the receptor count — is the distinction that matters when reading claims made about any of the three.

Why brand names confuse the comparison

Semaglutide is marketed under more than one brand name for more than one authorised indication, which is why the same compound appears in conversation under different labels. The brand is a commercial name attached to a specific licensed presentation; the compound underneath is the same molecule.

Retatrutide has no brand name because it has no authorised presentation to attach one to. When a supplier gives a research compound a proprietary-sounding product name, that name describes their packaging — not an approval. Our legal categories guide sets out the distinction in full.

Comparing suppliers on the same basis

Because retatrutide is not a finished licensed product, presentations differ between suppliers: different vial quantities, different formats, and different documentation. To compare two offers, convert both to the same basis — quantity in milligrams, and purity as an analytically determined percentage.

The peptide calculator handles the quantity-to- concentration conversion once a vial is reconstituted, which is the step where most like-for-like comparisons go wrong.

Why the two sets of results are not directly comparable

Figures for these compounds almost always come from separate trials rather than a head-to-head study, and separate trials rarely share a design. They differ in how long they run, in the population enrolled, in what the comparator arm receives, and in which endpoint was specified as primary before the study began. Two percentages quoted side by side can therefore be measuring different things over different periods in different people.

Where a genuine direct comparison exists, the publication says so explicitly. Where it does not, the honest reading is that the compounds have been studied separately and their results sit alongside each other rather than against each other. That gap is wider for retatrutide than for semaglutide for a simple reason: a phase 2 programme generates far fewer comparisons than a completed authorisation package.

The practical test when reading any claim about an investigational compound is whether the number arrives with the study it came from. A figure with no citation attached is not evidence, and an uncited percentage is the most common way claims about research compounds get inflated.

Supply note. Peptiq supplies research compounds for laboratory research use only. We do not supply licensed medicines, we are not a pharmacy, and nothing on this page is guidance on use.