Cagrilintide is a lab-made, long-acting copy of a natural hormone called amylin. Amylin is released by your pancreas at the same time as insulin, right after you eat, and one of its jobs is to tell your brain you are full. Cagrilintide mimics that "I am full" signal but is engineered to last about a week instead of minutes. It is best known as the partner in CagriSema — the investigational combination with semaglutide.
In plain terms: it borrows a natural fullness hormone and makes it last long enough for a weekly injection.
What it is
Amylin is a small hormone — a 37-amino-acid peptide — that pancreatic beta cells release alongside insulin4. It reduces appetite, slows how fast the stomach empties, and helps you feel satisfied with less food. The problem for drug-makers is the same one GLP-1 faced: natural amylin clears from the body very quickly.
Cagrilintide solves that by attaching a fatty-acid chain to the peptide. That chain latches onto albumin, an abundant, long-lived blood protein, which shields the molecule from rapid breakdown4. An earlier amylin drug, pramlintide, lacked this trick and had to be injected several times a day; cagrilintide is designed for once-weekly use.
You may also see it written cagrilintide acetate (the acetate salt form) or misspelled *cagrilinitide* or *cagrilitide* — these all refer to the same molecule, whose development code was AM833.
How it is thought to work
Cagrilintide switches on amylin receptors in the brainstem — specifically two small regions called the area postrema and the nucleus of the solitary tract, which help govern satiety (the feeling of having eaten enough) and meal size4. This is a different appetite system from the one GLP-1 drugs use.
In plain terms: semaglutide pulls the GLP-1 lever; cagrilintide pulls a separate amylin lever. Because they are different levers on appetite, pushing both at once tends to add up — which is the whole logic behind combining them.
There may be more to it than eating less. In rats, roughly a third of the combination's weight loss came not from reduced food intake but from preserving energy expenditure — blunting the metabolic slowdown that normally fights back against weight loss6. That is animal data, so read it as mechanism rather than proof, but it hints at why the pairing can outrun either drug alone.
Pharmacokinetics — why once a week
Cagrilintide's reported half-life (how long it takes for half a dose to clear) is roughly 159-195 hours, or about 7-8 days4. Peak blood levels arrive one to three days after an injection, and with weekly dosing the level builds over about five weeks to a steady plateau. That week-long duration is what makes a once-weekly schedule possible — the same design principle behind semaglutide.
Two 2026 studies also found that reduced kidney or liver function did not meaningfully change how cagrilintide is cleared, or its safety and tolerability7. For the decay curve and clearance math, see the cagrilintide half-life reference.
What the trials actually found
Cagrilintide stands apart from most research peptides because it has genuine human trial data, and that data built up quickly over a few years. Note the model and dose in each row:
| Study | People | Key result | Year |
|---|---|---|---|
| Enebo et al. — phase 1b2 | 95 adults with overweight | Adding cagrilintide to semaglutide 2.4 mg produced more weight loss over 20 weeks than semaglutide alone — the proof-of-concept for the combination | 2021 |
| Lau et al. — phase 21 | ~700 adults with overweight/obesity | Cagrilintide alone (top 4.5 mg dose) gave about 10.8% weight loss over 26 weeks, versus roughly 3% on placebo | 2021 |
| Garvey et al. — REDEFINE 1 phase 33 | ~3,400 adults without diabetes | CagriSema (cagrilintide + semaglutide) reached about 20.4% average weight loss at 68 weeks (~22.7% with full adherence) vs 3% placebo | 2025 |
| Davies et al. — REDEFINE 2 phase 35 | 1,206 adults with obesity and type 2 diabetes | CagriSema gave -13.7% weight loss at 68 weeks (vs -3.4% placebo); 73.5% reached an HbA1c of 6.5% or lower (vs 15.9% on placebo) | 2025 |
Read those rows as a story. First, a small phase-1b study showed the combination idea worked — cagrilintide added to semaglutide beat semaglutide alone2. Then a larger phase-2 trial showed cagrilintide could produce meaningful weight loss on its own1. Then the phase-3 REDEFINE trials confirmed the combination at scale — first in obesity3, then in people with type 2 diabetes5.
Latest research (2025-2026)
The freshest and most important data is the REDEFINE phase-3 program, published in 2025:
- In REDEFINE 1 (about 3,400 adults with overweight or obesity but without diabetes), once-weekly CagriSema produced an average weight loss of roughly 20.4% at 68 weeks — about 22.7% among participants who stayed fully on treatment — compared with about 3% on placebo3. Around 60% of the CagriSema group lost at least 20% of their body weight.
- In the same trial CagriSema also outperformed semaglutide alone (~14.9%) and cagrilintide alone (~11.5%), which is the clearest demonstration yet that the two hormones add up3.
- Reported secondary effects in that trial included improvements in blood pressure, waist circumference, and blood-sugar measures3. These are studied trial outcomes, described as reported — not a promise about any individual.
- REDEFINE 2 extended the combination to people with type 2 diabetes: in 1,206 adults, CagriSema produced about 13.7% weight loss at 68 weeks versus 3.4% on placebo, and 73.5% reached an HbA1c of 6.5% or lower (versus 15.9% on placebo)5. Weight loss runs lower in diabetes than in the non-diabetes REDEFINE 1 (~20%) — a pattern seen across obesity drugs — but the blood-sugar benefit was large.
- The phase-3 program has kept widening through 2025-2026 across obesity and type 2 diabetes, and independent systematic reviews now pool these trials to the same broad conclusion: CagriSema beats semaglutide alone, at the cost of more gastrointestinal side effects8.
Keep the honesty in view: these are trial results for an investigational combination, not an approved product with years of real-world use. We update this section as further REDEFINE data and any regulatory decisions land.
Side effects and safety
Like GLP-1 drugs, cagrilintide's most common side effects are gastrointestinal — nausea, vomiting, diarrhoea, and constipation. In the REDEFINE 2 trial, gastrointestinal side effects were reported by about 72.5% of people on CagriSema versus 34.4% on placebo, but most were transient and mild-to-moderate5. Pooled analyses across the trials describe the same trade-off: more weight loss than semaglutide alone, alongside more of these gut side effects8.
Because it is investigational, cagrilintide has no long-term, real-world safety record, and the trials studied selected groups of people. This page describes what the studies reported — it is not medical advice, and decisions about any medicine belong with a qualified clinician.
Regulatory status
Cagrilintide is not an approved medicine as of 2026. It has completed phase-2 and phase-3 trials but has no regulatory approval for any use, alone or as CagriSema. This page explains what it is and what the trials showed — not how to use it — and it takes no position on sourcing.
The short version
Cagrilintide is a long-acting amylin analog: a lab-made copy of a natural fullness hormone, engineered to last about a week. On its own it produced roughly 11% weight loss in a phase-2 trial, but its real story is the combination with semaglutide — CagriSema — which reached about 20% weight loss in obesity (REDEFINE 1) and about 13.7% in people with type 2 diabetes (REDEFINE 2), with mainly gastrointestinal side effects. It is investigational, not approved. Educational overview only, not medical advice.