What Is Cagrilintide? The Amylin Peptide Behind CagriSema

Amylin works mainly through the brain, especially the area postrema and hypothalamus, which help control fullness. In research settings, amylin signaling has three main effects:

• Earlier fullness: it increases satiety so meals end sooner.
• Slower stomach emptying: food leaves the stomach more gradually, which blunts blood sugar spikes after meals.
• Less glucagon after eating: it reduces the post-meal release of glucagon, a hormone that raises blood sugar.

How it differs from GLP-1 drugs. Semaglutide and tirzepatide act on GLP-1 (and, for tirzepatide, GIP) receptors. Amylin uses a separate receptor system, so the two approaches can add together. That complementary mechanism is the scientific rationale for combining cagrilintide with semaglutide in one weekly shot.

Cagrilintide on its own. In a 26-week phase 2 trial published in The Lancet in 2021, adults with obesity taking the highest dose of cagrilintide lost about 10.8% of body weight, compared with about 9% for liraglutide 3.0 mg and 3% for placebo. That made it the first amylin analog to show weight loss in the same range as an approved GLP-1 drug.

CagriSema (cagrilintide plus semaglutide). The larger story is the combination. In the phase 3 REDEFINE 1 trial of 3,417 adults, people who stayed on CagriSema lost an average of 22.7% of body weight at 68 weeks, versus 2.3% on placebo. More than 9 in 10 participants lost at least 5% of their weight.

Head-to-head with tirzepatide. In REDEFINE 4, announced in February 2026, CagriSema produced about 23% weight loss at 84 weeks but did not meet its goal of proving non-inferiority to tirzepatide 15 mg, which reached about 25.5%. Novo Nordisk is now testing higher-dose combinations.

Because amylin slows the stomach, the most common side effects are gastrointestinal, much like GLP-1 drugs. In REDEFINE 1, digestive side effects affected about 80% of people on CagriSema versus about 40% on placebo. The most reported were:

• Nausea (about 55% vs 13% on placebo)
• Constipation (about 31% vs 12%)
• Vomiting (about 26% vs 4%)

Most events were mild to moderate and occurred while the dose was being increased. Discontinuation due to side effects was 5.9% with CagriSema versus 3.5% with placebo. Long-term safety data for cagrilintide on its own are more limited than for semaglutide.

No. As of October 2026, neither cagrilintide nor CagriSema is FDA-approved. Novo Nordisk submitted a New Drug Application for CagriSema on December 18, 2025, and the company has said it expects an FDA decision in the fourth quarter of 2026. Cagrilintide on its own is not under FDA review as a standalone drug.

Products labeled “cagrilintide” from research suppliers are sold for laboratory research only. They are not the same as a pharmaceutical product and are not intended for human use.

Cagrilintide is one of several newer metabolic peptides. Each uses a different hormone pathway, which is why researchers increasingly study them in combination rather than alone.

Amylin vs GLP-1. GLP-1 drugs mainly act on gut-brain signaling and insulin release. Amylin analogs act on brain areas that control fullness and on the stomach’s emptying speed. Early research also suggests amylin-based weight loss may preserve a slightly different mix of fat and lean tissue, though this is still being studied.

Eloralintide is a newer, more selective amylin-receptor agonist from Eli Lilly. It is earlier in development than cagrilintide and has not been tested in a combination product at the same scale.

Products sold as cagrilintide by research suppliers are laboratory chemicals, not medicines. They are not made under drug manufacturing rules, so quality varies a lot between vendors. If you are evaluating a cagrilintide supplier for lab research, these are the checks that matter:

• Batch-specific COA: the certificate should match the lot number on your vial, not a generic sample.
• Independent lab: testing should come from a named third-party lab, ideally with a way to verify the report online.
• Identity, not just purity: HPLC purity alone does not confirm the right molecule; look for mass spectrometry (MS) identity confirmation.
• Endotoxin and sterility results: these matter for any injectable research material.
• Correct fill amount: the measured content should be close to the labeled milligrams.

Our Trusted Sources page lists vendors we track, with current community codes. Our guide to reading a certificate of analysis explains each line of a COA.

• Cagrilintide is a once-weekly amylin analog that increases fullness and slows stomach emptying.
• On its own it produced about 11% weight loss in a 26-week phase 2 trial.
• Combined with semaglutide as CagriSema, it reached about 23% weight loss in phase 3.
• CagriSema fell short of matching tirzepatide head-to-head in REDEFINE 4.
• It is not FDA-approved; an FDA decision on CagriSema is expected in late 2026.

What is cagrilintide?

Cagrilintide is a long-acting synthetic analog of amylin, a pancreatic hormone that increases fullness and slows stomach emptying. It is studied as a once-weekly injection for obesity.

Is cagrilintide the same as semaglutide?

No. Semaglutide is a GLP-1 receptor agonist, while cagrilintide acts on amylin and calcitonin receptors. CagriSema combines the two in one injection.

How much weight loss did cagrilintide show?

On its own, about 10.8% at the highest dose over 26 weeks. Combined with semaglutide as CagriSema, about 22.7% at 68 weeks in REDEFINE 1.

Is cagrilintide FDA-approved?

No. CagriSema was submitted to the FDA in December 2025, and Novo Nordisk expects a decision in Q4 2026. Cagrilintide alone is not under FDA review.

What are the side effects of cagrilintide?

Mostly digestive: nausea, constipation and vomiting, especially while the dose is increased. These are similar to GLP-1 side effects.

• The Lancet – Cagrilintide phase 2 trial in people with obesity (2021)
• Novo Nordisk – CagriSema New Drug Application announcement (December 18, 2025)
• Drugs.com – CagriSema FDA approval status and REDEFINE 4 results (February 2026)
• Patient Care Online – CagriSema NDA and REDEFINE 1 adverse event data
• Pharmacological Reviews – Hay et al., amylin receptor pharmacology