Two of these have completed FDA review. One is investigational, and its safety and effectiveness have not been established — which is why no valid comparison between them exists.
People search for this expecting a side-by-side table. There isn't one here, and the reason is not evasion.
Semaglutide and tirzepatide have completed FDA review for chronic weight management. Retatrutide has not. It is an investigational drug, which means it may be used only in clinical research and that its safety and effectiveness have not been established for any use.
Setting an investigational drug against approved medications means representing it as equivalent, superior, or inferior to them. None of those representations is supportable, and FDA regulation governing investigational drugs (21 CFR 312.7) prohibits them. So the honest answer is that this comparison does not exist yet — not that we are withholding it.
Set the regulatory question aside for a moment. The evidence needed to make this comparison has never been generated.
A head-to-head trial randomly assigns participants drawn from one population to one drug or another, then measures them against the same endpoints over the same period. That design is what allows a difference between two drugs to be attributed to the drugs. No such trial has compared retatrutide with semaglutide or tirzepatide.
What exists instead is separate trials, run in different populations, over different durations, against different endpoints. Lining up figures from separate studies and treating the gap between them as a result is not a valid method: it captures the differences between the studies as much as anything about the drugs. This is a general limitation of cross-study comparison rather than something peculiar to these three.
These three are often ranked by how many receptors they bind — semaglutide one (GLP-1), tirzepatide two (GLP-1 and GIP), retatrutide three (GLP-1, GIP, and glucagon).
That is a description of molecular design, not a ranking. Binding more receptors does not establish that a drug works better, that it is safer, or that it is tolerated as well. Whether a given molecule helps anyone is settled by clinical trials and regulatory review, and for retatrutide that has not been settled.
Treating the receptor count as a scoreboard is the most common error in how these three get written about, and it is worth naming because it looks like technical detail rather than the claim it actually is.
One comparison can be made, because it is a matter of public record rather than a claim about effect.
Semaglutide has completed FDA review and is marketed as Wegovy for chronic weight management and as Ozempic for type 2 diabetes.
Tirzepatide has completed FDA review and is marketed as Zepbound for chronic weight management and as Mounjaro for type 2 diabetes.
Retatrutide has not been approved by the FDA for any indication. It cannot lawfully be prescribed, dispensed, or compounded by anyone, and Weight Method does not offer it.
Compounded preparations of semaglutide and tirzepatide are dispensed by licensed pharmacies under the compounding statutes. Those preparations are a separate regulatory category from the approved brand products named above: they are not themselves FDA-approved and are not reviewed by the FDA for safety or effectiveness.
If you are deciding what to do about weight management now, retatrutide is not one of the options, so a three-way comparison is not the decision actually in front of you.
The useful conversation is with a licensed provider, about the options that are lawfully available and whether any of them suits your health history. That is a clinical judgment that depends on your history, not something a table settles.
And treat anything sold online under the retatrutide name as what it is: an unapproved product from outside the lawful supply chain, whose contents nobody has verified.