TL;DR: Zepbound and Mounjaro both contain tirzepatide. Wegovy and Ozempic both contain semaglutide. Retatrutide has no brand name at all, because brand names go to approved medicines and retatrutide is still investigational. So every "retatrutide vs [brand]" question reduces to one of two mechanistic comparisons, plus a regulatory difference that matters more than the mechanism does. Retatrutide is supplied for research use only.
The Brand Names, Decoded
Much of the confusion in this area is vocabulary rather than pharmacology. Four widely recognized brand names cover just two compounds.
| Brand name | Compound | Receptors | Approved indication |
|---|---|---|---|
| Ozempic | Semaglutide | GLP-1 | Type 2 diabetes |
| Wegovy | Semaglutide | GLP-1 | Weight management |
| Mounjaro | Tirzepatide | GLP-1 + GIP | Type 2 diabetes |
| Zepbound | Tirzepatide | GLP-1 + GIP | Weight management |
| — none — | Retatrutide | GLP-1 + GIP + glucagon | None — investigational |
Ozempic and Wegovy are the same molecule marketed for different indications at different dose ranges. Mounjaro and Zepbound have exactly the same relationship. Once that collapses, "retatrutide vs Zepbound" is simply retatrutide vs tirzepatide, and "retatrutide vs Wegovy" is retatrutide vs semaglutide.
Why Retatrutide Has No Brand Name
Brand names are commercial identities attached to approved products. A compound acquires one when a regulator approves it for a specific indication and the manufacturer markets it under that name.
Retatrutide has not reached that stage. It is identified by its generic name and by its Eli Lilly development code, LY3437943. The absence of a brand name is not a naming oversight — it is a direct signal of where the compound sits in development, a point our FDA approval status article covers in full.
The Mechanistic Comparison
Reduced to receptors, the lineage is straightforward and cumulative.
- Semaglutide (Ozempic, Wegovy) — GLP-1 receptor only. Appetite signalling and glucose-dependent insulin release.
- Tirzepatide (Mounjaro, Zepbound) — GLP-1 plus GIP. Adds the second incretin receptor, with additional effects on insulin sensitivity and nutrient handling in fat tissue.
- Retatrutide — GLP-1, GIP, and glucagon. Adds a non-incretin receptor associated with energy expenditure and hepatic fat mobilization.
Each step retains the previous receptors and adds one. That is why the class is usually described as generational rather than as a set of alternatives. Our triple-agonist explainer covers why the glucagon arm holds together with the other two rather than working against them.
What the Published Numbers Show
Across separate published trials, the effect sizes follow the receptor count.
| Compound | Top dose studied | Reported mean weight reduction | Trial phase |
|---|---|---|---|
| Semaglutide | 2.4 mg weekly | ~15% at 68 weeks | Phase 3 |
| Tirzepatide | 15 mg weekly | ~21% at 72 weeks | Phase 3 |
| Retatrutide | 12 mg weekly | ~24% at 48 weeks | Phase 2 |
Two things are worth noticing. The retatrutide figure is the largest and was reached in the shortest time. It is also the only one from a Phase 2 trial rather than a Phase 3 programme — a smaller population and an earlier stage of characterization. These are not head-to-head studies, and the populations and durations differ, so the ordering is suggestive rather than decisive.
The Difference That Matters More Than Mechanism
Focusing on receptor counts and effect sizes can obscure the more consequential distinction between these compounds.
Semaglutide and tirzepatide have completed Phase 3 development, undergone regulatory review, and accumulated post-marketing surveillance data across large populations. Their safety profiles are characterized to a standard that took years and many thousands of participants to reach.
Retatrutide has a single published Phase 2 trial. Its Phase 3 programme is running now. The gap between those two evidentiary positions is not a technicality, and it is not closed by a larger weight-reduction figure. A more advanced mechanism and a less complete safety characterization are entirely compatible — retatrutide currently has both.
Effect size describes what a trial measured. It says nothing about how thoroughly the compound has been characterized. Conflating the two is the most common error in this comparison.
What Helix North Supplies
Helix North stocks retatrutide and tirzepatide as research materials, with third-party Certificates of Analysis published on the product pages where available. Semaglutide is not currently in the catalog. These are lyophilized research compounds — not the branded products described above, which are prescription medicines available only through licensed channels.
For sourcing, vial sizes, and testing methodology, see our buy retatrutide in Canada guide and the GLP research hub. The plain-language three-way comparison is a good starting point if the terminology is new.
For Research Use Only
All discussion above describes clinical-trial research and compound pharmacology. Brand-name products referenced here are prescription medicines and are named only to clarify which compound each contains. Helix North supplies retatrutide for research applications only — not for human or animal consumption, and nothing here constitutes medical, dosing, or clinical guidance.
