Owned and operated by a cf veteran 
Two research peptides. Two different jobs. Here is the simple version for Canadians, with the trial numbers side by side.
- Retatrutide copies three hormones
- Cagrilintide copies one: the “full” one
- Best trial result 28.3% vs 11.5%
- At Red Leaf reta in stock, cagri on the way
These two are not really rivals. They pull different levers.
Retatrutide copies three hormone signals at once. It works on hunger, on blood sugar, and on how fast the body burns fuel.
Cagrilintide copies one signal. It copies amylin. Amylin is the hormone that tells the brain you are full.
On its own, retatrutide moved the scale much further in trials. Cagrilintide was built to work beside another compound, not alone. Neither one is an approved medicine yet. Red Leaf sells retatrutide for laboratory research only.
Three targets: GLP-1, GIP and glucagon. One shot a week in trials. Best result on its own: 28.3% at 80 weeks. In stock at Red Leaf.
One main target: amylin, the “you are full” hormone. One shot a week in trials. Best result on its own: 11.5% at 68 weeks. Coming to Red Leaf.
Research use only. Everything below reports published study results. Red Leaf Research Labs sells research chemicals for laboratory use. Nothing here is medical advice, a dose plan, or a promise of any result. Not for human or animal use.
The short version
- Retatrutide works on three targets. Cagrilintide works on one.
- Both were given once a week in trials.
- Both stay in the body about a week.
- Retatrutide alone: 28.3% body weight lost at 80 weeks, top dose.
- Cagrilintide alone: 11.5% at 68 weeks.
- Cagrilintide is almost always studied with a partner compound.
- Paired that way, it reached 20.4%.
- Neither is approved as a medicine. Both are trial-stage.
- Upset stomach is the top complaint for both.
- Red Leaf stocks retatrutide today. Cagrilintide is coming.
What retatrutide is
Retatrutide is a lab-made peptide. A peptide is a short chain of amino acids. Think of it as a very short protein.
It is often called a triple agonist. That word just means it presses three buttons.
The three buttons are GLP-1, GIP, and glucagon. Those are real hormones your body already makes.
GLP-1 slows the stomach and cuts hunger. GIP helps handle sugar and may soften nausea. Glucagon nudges the body to burn stored fuel.
Most weight-loss compounds press one or two of those. Retatrutide presses all three. That third button, glucagon, is the part that makes it different. It is about output, not just intake.
We go deeper on the compound itself in retatrutide vs Ozempic and in our three-way comparison.
What cagrilintide is
Cagrilintide is also a lab-made peptide. Its research code name is AM833.
It copies a hormone called amylin. Your pancreas releases amylin with insulin after you eat.
Amylin has a simple job. It slows the stomach down. It tells the brain the meal is done. It keeps the “I am full” feeling going a bit longer.
Natural amylin breaks down in minutes. That is no use in a study. So cagrilintide was redesigned to hang on to a blood protein called albumin. That is what stretches it out to about a week.
It also touches calcitonin receptors. Researchers call it a dual amylin and calcitonin receptor agonist. That is a mouthful. The short version is: one main signal, sent for a long time.
One picture: three switches and a full tank
Here is the easiest way to hold the difference in your head.
Picture the body as a car.
Retatrutide is a hand on three controls at once. It eases off the gas. It changes the fuel mix. It also opens the tap on the reserve tank so stored fuel gets used.
Cagrilintide is a better fuel gauge. It does not change the engine. It makes the “tank full” light come on sooner, and stay on longer.
A better gauge helps. A hand on three controls does more. That is the whole comparison in one line.
A map of what each one touches. Not to scale, and not a picture of the molecules.
Why these two get compared
They came up at the same time. Both are weekly. Both are peptides. Both are aimed at body weight. So people line them up.
But the trials treat them differently. Retatrutide is tested alone and judged alone. Cagrilintide is mostly tested as half of a pair.
That is the trap in most comparisons online. They put a solo number next to a team number and call it a fair fight. It is not.
Side by side
Same facts, in a grid.
| Retatrutide | Cagrilintide | |
|---|---|---|
| Copies | GLP-1, GIP and glucagon | Amylin |
| Buttons pressed | Three | One main one, plus calcitonin |
| Other name | LY3437943 | AM833 |
| Shot schedule in trials | Once a week | Once a week |
| Time in the body | About 6 days | About a week |
| Best result alone | 28.3% at 80 weeks | 11.5% at 68 weeks |
| Usually studied | On its own | Paired with semaglutide |
| Approved as a medicine | No | No |
| Comes as | Freeze-dried powder | Freeze-dried powder |
| At Red Leaf | In stock now | On the way |
What the trials showed
Numbers matter more than theory. Here are the headline ones.
Retatrutide finished a large phase 3 study called TRIUMPH-1. It ran 80 weeks and enrolled 2,339 adults. Results were shared in May 2026.
Average weight lost was 19.0% on the low dose, 25.9% in the middle, and 28.3% on the top dose. A smaller group carried on to 104 weeks and averaged 30.3%. At the top dose, 45.3% of people lost at least 30% of their body weight.
Cagrilintide’s biggest read-out came from a study called REDEFINE 1. It ran 68 weeks with 3,417 adults. Cagrilintide alone reached 11.5%. Semaglutide alone reached 14.9%. The two together reached 20.4%. A dummy shot reached 3.0%.
Different trials, different people, different lengths. This is not a head-to-head race. Read it as scale, not as a scoreboard.
That last line matters. Nobody has run retatrutide against cagrilintide in the same room with the same people. Anyone who tells you one “beat” the other is stretching it.
Can they be used together?
This is the question people ask most. It is also the newest science.
In September 2026, a paper in Nature Metabolism put the two together in obese rats. Daily shots of both beat either one on its own. It also beat matched pairings built on semaglutide or tirzepatide.
The interesting part is why. The extra weight loss could not be explained by eating less alone. Blood markers improved too, including cholesterol, triglycerides and insulin.
The authors call it five-receptor polypharmacology. Plain version: five signals at once did more than three.
A five-signal approach is worth studying. The two peptides do not cancel each other out in animals.
This was rats, not people. Daily dosing, not weekly. No human trial of this pair has reported results.
So the honest answer is: promising in animals, unproven in humans.
Side effects seen in trials
Both compounds upset the gut. That is the pattern across this whole drug class.
In the retatrutide phase 3 study, nausea was reported by 28.6% to 42.4% of people, depending on dose. Diarrhea ran 25.2% to 32.0%. Constipation ran 23.8% to 26.1%. Vomiting ran 10.6% to 25.3%.
Drop-out climbed with dose too: 4.1% on the low dose, 6.9% in the middle, 11.3% at the top.
Cagrilintide trials reported the same family of complaints, led by nausea and vomiting.
- Complaints rise as the dose rises, in both.
- Most reports came early and eased with time.
- Going up fast is what people blamed most often.
- Trial results come from supervised studies, not home use.
We wrote a whole page on this for one of them: retatrutide side effects.
Getting them in Canada
Neither compound is approved as a medicine here. Both are sold as research chemicals. That is the whole legal picture in two lines.
Retatrutide is easy to find in Canada. Cagrilintide is harder. Fewer labs make it, and fewer Canadian sellers carry it.
Red Leaf stocks retatrutide in 10mg, 20mg and 30mg vials, shipped from inside Canada. No border. No customs surprise.
Cagrilintide is not on our shop yet. It is coming. If you want to know the day it lands, make a free account and we will tell you.
One more thing worth knowing. Some Red Leaf listings never appear on the shop page at all. Account holders see a small set of factory-lot deals that the public cannot. The 10mg retatrutide multi-vial pack is one of them, and the per-vial rate is well under the single-vial price. You have to be logged in to see it.
For current single-vial pricing, see retatrutide cost in Canada.
How to judge any seller
The compound matters less than who you buy it from. Run this list on us too.
- A real lab reportMade for that exact batch, with a date on it.
- A name you can checkThe testing lab should be one you can look up.
- Purity and massBoth numbers. Purity alone hides an underfilled vial.
- Ships from CanadaAsk where it leaves from, not where the site is registered.
- Clear labelsCompound, size, lot, and a research-use line.
- A real address and a humanAsk a hard question and see what comes back.
Our reports are posted before anyone asks. See our testing page, or the longer buyer’s guide.
Research vials at Red Leaf
Retatrutide sizes in stock
Free express shipping over this
Batches with a lab report
Ships from within Canada
Everything below ships from Canada with its own certificate of analysis.
RetatrutideFrom $79.99
TirzepatideFrom $54
MOTS-c Peptide 40mgFrom $119
5-AMINO-1MQ 50mgFrom $130
Bacteriostatic WaterFrom $10
Peptide Pens Canada – Red Leaf Research Pen Add-OnFrom $99Mixing with bacteriostatic water? Our peptide calculator does the arithmetic for you. Trial dose figures are collected on the retatrutide dosing chart page, reported as published, not as advice.
Common questions
What is the main difference between retatrutide and cagrilintide?
Retatrutide copies three hormones. Cagrilintide copies one, amylin.
Which one lost more weight in trials?
Retatrutide, by a wide margin, when each was used alone.
Can cagrilintide and retatrutide be used together?
It has been tested in rats, not in people. The rat study came out in September 2026.
How long does cagrilintide last?
About a week. That is why trials used one shot a week.
How long does retatrutide last?
About six days. Also a weekly shot in trials.
Is AM833 the same as cagrilintide?
Yes. AM833 is its research code name.
Is cagrilintide the same as CagriSema?
No. CagriSema is cagrilintide plus semaglutide, given together.
Is retatrutide just another GLP-1?
No. GLP-1 is only one of its three targets.
Do they come ready to use?
No. Both arrive as a dry powder and are reconstituted in the lab.
Are they approved as medicines?
No. Both are still in clinical research.
Does Red Leaf sell cagrilintide?
Not yet. It is on the way. Retatrutide is in stock now.
Is cagrilintide a GLP-1 drug?
No. It copies amylin, a different hormone with a different job.
Why is cagrilintide harder to find in Canada?
Fewer labs produce it, so fewer Canadian sellers carry it.
Which one should a study use?
That depends on the question. One signal or three is the real choice, not better or worse.
10mg, 20mg and 30mg vials. Batch lab report on every one. Free express shipping over $250.
Sources: the TRIUMPH-1 phase 3 results as reported by AJMC; the phase 2 retatrutide trial in the New England Journal of Medicine; the REDEFINE 1 cagrilintide-semaglutide trial, also in the New England Journal of Medicine; and the combination study in Nature Metabolism, September 15 2026. Red Leaf Research Labs supplies research chemicals for laboratory use only. Not for human or animal use. No medical advice is given or implied.
