The Peptide Nook

Cagrilintide

In plain English

Cagrilintide is a long-acting copy of amylin, a hormone released with insulin after meals that helps you feel full. It reduces appetite through a different pathway from GLP-1 peptides, so it can be used alone or combined with semaglutide for extra weight loss. It is injected once a week.

What it's used for

  • Weight loss, alone or with semaglutide
  • Appetite and portion control
  • Blood-sugar control in type 2 diabetes (with semaglutide)

Benefits

In human studies, cagrilintide has shown:

  • About 11% average weight loss over 26 weeks at 4.5 mg weekly when used alone (phase 2)
  • About 12% average weight loss over 68 weeks at 2.4 mg weekly alone, and about 20% when combined with semaglutide 2.4 mg as CagriSema (REDEFINE 1)
  • Feeling full sooner and eating less at meals

Users report that adding cagrilintide to a GLP-1 peptide helps with “food noise” and plateaus.

How it works

In simple terms: cagrilintide adds a second fullness signal on top of GLP-1.

It activates amylin and calcitonin receptors in the brain, which slow stomach emptying, reduce appetite and lower the release of glucagon after meals. Because this pathway is separate from GLP-1, combining the two produces more weight loss than either alone. A fatty-acid side chain gives it a long half-life for once-weekly dosing.

Development history

  • 2010s: Developed by Novo Nordisk as a long-acting amylin analog.
  • 2021: Phase 2 results published in The Lancet.
  • 2025: Phase 3 REDEFINE results published in the New England Journal of Medicine, showing about 20% weight loss with CagriSema.

Typical protocols

Educational information only, not medical advice. The information below describes how this peptide has been used in research, on prescription labels or by users. It is not a recommendation. Talk to a qualified healthcare professional before starting, stopping or changing anything.

In clinical studies, cagrilintide was stepped up gradually to 2.4 mg weekly:

Weeks Weekly dose
1–4 0.25 mg
5–8 0.5 mg
9–12 1 mg
13–16 1.7 mg
17 onward 2.4 mg (maintenance)

In CagriSema studies, semaglutide was stepped up on the same schedule. Users report following this pattern, often adding cagrilintide to an existing GLP-1 peptide at the lowest step.

Cycling

Used continuously in studies. Appetite and weight tend to return after stopping.

Administration options

Subcutaneous injection once a week, on the same day each week.

Reconstitution and dosing calculator

Cagrilintide is commonly sold in 5 mg or 10 mg vials and mixed with 2 mL of bacteriostatic water.

1Peptide in the vial

The total amount printed on the vial label.

2Bacteriostatic water added

More water makes each dose a bigger, easier-to-measure draw. It does not change how much peptide is in the vial.

3Dose per injection

Use the dose from your protocol or your clinician. 1 mg = 1,000 mcg.

4Your syringe

All three are U-100 insulin syringes: 100 units = 1 mL. Smaller barrels make small doses easier to read.

Draw your syringe to

– units

Volume to draw
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Concentration
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Each unit holds
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Doses per vial
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Show the math

    This tool does arithmetic only. It does not choose a dose or confirm that any substance is right for you. Double-check every result against your syringe and your clinician’s instructions.

    Side effects and safety

    • Most common: nausea, constipation, diarrhea, vomiting and tiredness, mostly during dose increases. Stomach side effects are more frequent when combined with semaglutide.
    • Injection-site reactions.
    • Shared cautions with GLP-1 type peptides: gallbladder problems, dehydration and pancreatitis.
    • Avoid during pregnancy and breastfeeding.

    Common stacks

    • Semaglutide: the CagriSema combination, the most studied pairing.
    • Users report adding it to tirzepatide or retatrutide, though these combinations have not been studied.

    Storage

    Powder: refrigerate, dry and away from light.
    After mixing: refrigerate at 2–8 °C and protect from light.

    Compare with

    • Semaglutide: GLP-1 peptide; stronger alone, but cagrilintide adds to its effect.
    • Pramlintide: an older, short-acting amylin medicine taken with meals.
    • Eloralintide: a newer amylin peptide in development.

    Frequently asked questions

    Can cagrilintide be used on its own?

    Yes. Used alone it produced about 11–12% average weight loss in studies, less than semaglutide but meaningful.

    What is CagriSema?

    A once-weekly combination of cagrilintide and semaglutide that produced about 20% average weight loss in studies.

    Do I need to step up the dose?

    Studies stepped up every 4 weeks over 16 weeks to reduce stomach side effects, and users follow the same approach.

    References

    1. Lau DCW, et al. Once-weekly cagrilintide for weight management in people with overweight and obesity: a multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial. Lancet. 2021;398:2160-2172.
    2. Garvey WT, et al. Coadministered cagrilintide and semaglutide in adults with overweight or obesity (REDEFINE 1). N Engl J Med. 2025.
    3. ACC. REDEFINE 1 and REDEFINE 2 journal scan (2025). https://www.acc.org/Latest-in-Cardiology/Journal-Scans/2025/07/02/14/43/REDEFINE-1-and-REDEFINE-2
    Educational information only. Not medical advice. Always consult a qualified healthcare professional.

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