Carl read the papersWhat it actually is
Amylin is a hormone your pancreas releases alongside insulin every time you eat. It is a satiety signal — it tells you the meal is over. Cagrilintide is a synthetic, long-acting version of it, engineered to survive long enough for once-weekly dosing.
It keeps getting lumped in with the GLP-1 compounds and it is not one. That distinction is the whole point of the molecule: amylin works through a different receptor on a different appetite pathway, which is why adding it to a GLP-1 stacks rather than overlaps.
How it’s thought to work
- Amylin receptor agonism — Binds amylin receptors — calcitonin receptors paired with RAMP proteins — concentrated in the area postrema, nucleus tractus solitarius and hypothalamus.
- Meal-size reduction — Shortens the meal rather than dulling appetite all day. People describe getting full early rather than never getting hungry.
- Slowed gastric emptying — Food leaves the stomach more slowly — also the source of most of the nausea.
- Hedonic vs homeostatic appetite — The interesting part: amylin leans on reward-driven eating, where GLP-1 leans on homeostatic hunger. Two different problems, which is why the combination outperforms either alone.
What the research says
Unusually solid for this shelf: phase 3, 3,417 people, 68 weeks (REDEFINE 1). Cagrilintide 2.4 mg alone produced 11.8% weight reduction against 2.3% for placebo. The headline result was the combination — CagriSema reached 22.7%, against 16.1% for semaglutide 2.4 mg on its own. Most compounds documented here are running on rodent data; this one is not.
- REDEFINE 1 (phase 3, n=3,417, 68 wks) — 11.8% reduction on cagrilintide 2.4 mg monotherapy.
- Combination with semaglutide (CagriSema) reached 22.7% — meaningfully above either component alone.
- Mechanistically distinct from GLP-1, which is the argument for stacking rather than switching.
- Side-effect profile is dominated by GI: nausea, early fullness, constipation — heaviest during titration.
Watch: Cagrilintide explained
Video by Weight Medicine with Dr. Meghan MD on YouTube. Not affiliated with Peptide Carl and not an endorsement — included because a second explanation of the same mechanism is often what makes it click.
Reported protocols
These are the doses the peptide community actually reports running (Reddit & forums), alongside published research — logged for education, not as a recommendation to use.
| Parameter | Commonly reported range |
|---|---|
| Clinical ladder | 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg weekly, stepping every 4 weeks; trial target dose reached around week 17 |
| Community dose | Widely reported far lower and slower than the trial ladder — commonly 250 mcg 2–3×/week, or a 12–20 week titration instead of 16 |
| Frequency | Once weekly (the trial schedule); some report splitting the weekly amount across 2–3 smaller injections |
| Route | Subcutaneous — abdomen, thigh or upper arm, rotating sites |
| Cycle | Trials ran 68 weeks continuously; community cycles are typically far shorter |
| Community tip | The near-universal report is that going up too fast is the mistake — nausea and early fullness track the titration speed, not the final dose. Splitting the weekly dose is the most commonly reported fix. |
Common use cases
| Goal | Community protocol notes |
|---|---|
| Appetite / satiety on its own | low weekly dose, escalated slowly over 12–20 weeks |
| Added to a GLP-1 (CagriSema pattern) | the pairing the phase 3 data actually supports |
| Plateau on a GLP-1 alone | second mechanism rather than a higher dose of the first |
Mixing it (reconstitution)
Freeze-dried peptides must be reconstituted with bacteriostatic water before they can be measured. Carl’s calculator turns “mg in the vial + ml of water + target dose” into “units on the syringe” — and tells you how long the vial lasts.
→ Open the Reconstitution Calculator
Injection & handling
Subcutaneous, once weekly — abdomen, thigh or upper arm, rotating sites so you are not hitting the same spot every week. The long half-life is what makes weekly dosing possible; it also means a dose you regret stays with you for days, which is the argument for moving up slowly. Splitting the weekly amount into 2–3 smaller injections is the most commonly reported way to blunt the nausea. Reconstituted, keep it cold and out of the light.
Stacks it appears in
- CagriSema — Cagrilintide + semaglutide — the pairing the phase 3 programme was actually built around.
- With a triple agonist — Reported alongside retatrutide on the same different-pathway logic; no trial data supports this combination.
