Retatrutide vs tirzepatide vs cagrilintide

Retatrutide binds three receptors, GLP-1, GIP and glucagon. Tirzepatide binds two of those, GIP and GLP-1. Cagrilintide is not a GLP-1 peptide at all: it is a long-acting amylin analog acting at amylin and calcitonin receptors. Three molecules, three receptor sets.

Three molecules, three receptor sets

Receptor set is the first thing to compare, and it decides which of the three a model needs.

The numbers do not track the receptor count. Retatrutide binds the most receptors of the three and is the lighter of the two incretin peptides in this table, 82 g/mol below tirzepatide. Cagrilintide is lighter again, and it sits outside that family altogether. Its mass is a reference value until a certificate confirms it, which is why the observed mass on its own vial report is the figure that counts. Semaglutide vs tirzepatide vs retatrutide covers the single-receptor case both are built away from.

Why cagrilintide is not a GLP-1 peptide

Amylin is a hormone released alongside insulin. Cagrilintide is an engineered analog of amylin, lipidated so it lasts in research models. Its targets are the amylin receptors, which are calcitonin receptors paired with accessory proteins.

Semaglutide acts at the GLP-1 receptor, and the two molecules do not compete for a binding site. That non-overlap is the reason research pairs them: one amylin signal and one GLP-1 signal read at the same time. A pairing is two vials, two reports and two concentrations worked out separately, not one blended product. The cagrilintide vs semaglutide page takes that pair apart, and the semaglutide handling guide has the bench numbers for the GLP-1 side.

Two receptors or three

Tirzepatide was engineered from the GIP sequence to bind the GIP receptor and the GLP-1 receptor. Retatrutide started from the same sequence and added a third target, the glucagon receptor. Both are 39 residues, and both carry a C20 fatty diacid through a linker on a lysine. That chain is what binds albumin and stretches the half-life in research models from minutes to days.

The third receptor is the difference between the two, and it does not make the molecule bigger. Retatrutide is 82 daltons lighter at 4731.32 g/mol against tirzepatide's 4813.45. In research models, glucagon receptor activity raises energy expenditure and fat oxidation in the liver, while the GLP-1 activity beside it offsets the glucose side of that signal. Tirzepatide vs retatrutide works through the pair residue by residue, and mazdutide vs survodutide vs retatrutide covers the two other peptides built to include glucagon.

What tells them apart on a lab report

An identity check compares the observed mass on a report to the expected mass, within a tenth of a percent. At these sizes that window is roughly 4 to 5 daltons wide.

An 82 dalton gap is about sixteen times the tolerance, and a 306 dalton gap about sixty times it. No vial passes as the wrong one of these three. Purity is the other half of the report, and it answers a different question: a 99% pure sample of the wrong molecule is still the wrong molecule. Cagrilintide has one caveat. Its expected mass is a reference value pending certificate confirmation, and we leave its CAS number unpublished rather than print one we have not confirmed. Retatrutide and tirzepatide have formula, mass and CAS number on their product pages.

Handling, storage and buying

Every vial ships as lyophilized powder, and the handling is the same across all three: run the water down the glass wall, swirl and never shake, keep the dry vial in the freezer and the solution in the fridge. Retatrutide reconstitution and storage covers the technique, which does not vary between them.

What does change is the molar math, because the same milligram figure is a different number of micromoles for each. Ten milligrams is 2.26 micromoles of cagrilintide, 2.11 of retatrutide and 2.08 of tirzepatide. If your work is in molar units, the molecular weight matters as much as the vial size on the label.

All three are sold in Canada as research chemicals for laboratory use, not as drugs, and are research peptides legal in Canada sets out where that line sits. That is general information, not legal advice.

Every retatrutide, tirzepatide and cagrilintide vial from pepuro ships free, from our Calgary, Toronto and Vancouver distribution centers, the same business day your e-Transfer clears, with a QR code on the vial that opens its independent, third-party lab report.

For research use only. Not for human or animal consumption.