What the cagrilintide peptide is and how it works: amylin, appetite and what the trials measured

Natural amylin is co-secreted with insulin from the beta cells of the pancreas when food reaches the small intestine. It acts as a satiety signal in the brain, slows gastric emptying and suppresses the glucagon response after meals ^[1]. The first amylin drug, pramlintide, is an approved treatment for diabetes that produces small weight losses ^[1].

Cagrilintide is a newer, long-acting acylated amylin analogue, meaning a fatty-acid chain is attached to the peptide ^[1]; its measured half-life is about a week ^[5]. It is classed with pramlintide as an amylin receptor agonist ^[6].

When people search for the "cagri peptide" they usually mean one of two things: the investigational drug in Novo Nordisk's trials, or powder sold online under the same name. The trial results on this page describe the first. Nothing sold outside the trials has been shown to contain the same molecule at the stated amount, and this site does not describe sources or products.

Amylin does not have a receptor of its own. Its receptors are built from the calcitonin receptor (CTR) paired with one of three receptor activity-modifying proteins, which makes three amylin receptors: AMY1R, AMY2R and AMY3R ^[9]. Cagrilintide activates the amylin receptors and the calcitonin receptor alone, which is why it is described as a dual amylin and calcitonin receptor agonist (DACRA) ^[7]. Cryo-electron microscopy structures published in 2025 show it binding AMY1R and CTR in a similar way and activating both without selectivity ^[7].

Where it acts

The appetite effect runs through the brainstem. In mice fed a high-fat diet, cagrilintide lowered body weight in normal animals, but its potency fell in mice lacking the proteins that form AMY1R and AMY3R, and its activation of neurons in the area postrema dropped by 57% ^[9]. The authors concluded that cagrilintide depends on AMY1R and AMY3R to lower body weight ^[9].

A 2026 cross-species atlas of the dorsal vagal complex, covering rat, mouse and macaque brainstem, refined the picture. Cagrilintide changed gene activity in area postrema neurons, but switching those neurons on artificially did not change long-term food intake. The lasting effect ran through a separate group of Calcr/Prlh neurons in the nucleus of the solitary tract, a population conserved in humans; knocking down Prlh there abolished cagrilintide's effect in rats but not semaglutide's ^[10]. That is direct evidence that cagrilintide and semaglutide reduce eating through different cells, which is the rationale for CagriSema.

Satiety and gastric emptying

The effects people notice follow from amylin's physiology: earlier fullness, smaller meals and slower stomach emptying ^[1]. In rats, CagriSema produced 12% weight loss with a 39% reduction in food intake while energy expenditure was preserved, meaning the weight loss came mainly from eating less ^[11].

Two cautions. Most of the mechanism work is in animals, and the human evidence is about outcomes (weight, glucose), not about which neurons were engaged. And cagrilintide is not a GLP-1 drug: it reaches a different receptor family, which is why the cagrilintide vs semaglutide comparison is a comparison of two pathways rather than two versions of one.

In a phase 1b trial in which cagrilintide was given with semaglutide 2.4 mg, the half-life of cagrilintide was 159 to 195 hours across doses of 0.16 to 4.5 mg, with peak blood levels reached a median of 24 to 72 hours after injection ^[5]. Exposure rose in proportion to dose, and cagrilintide did not change how much semaglutide was in the blood ^[5]. A half-life close to seven days is what makes a once-weekly schedule possible, the same reasoning that applies to semaglutide, whose half-life in the same trial was 145 to 165 hours ^[5].

The long half-life has a practical consequence the trials designed around. Because the drug accumulates over several weeks, every trial raised the amount gradually: the phase 2 monotherapy trial used a dose-escalation period of up to 6 weeks ^[2], and the phase 1b trial stepped up every 4 weeks over 16 weeks ^[5]. The trial doses and escalation steps are set out, as what the trials administered, in cagrilintide dosage in the trials; the unit arithmetic is on the cagrilintide calculator. No dose has been established for any use outside a trial.

Cagrilintide has no approved use. It is being developed for two purposes, and every human result comes from trials in those groups:

• Weight management in adults with obesity, or with overweight and at least one weight-related condition. This is the indication Novo Nordisk sought for CagriSema in its December 2025 FDA application ^[4], and it is the population of the cagrilintide-alone phase 3 programme, RENEW 1 and RENEW 2, in people with and without type 2 diabetes ^[8].
• Type 2 diabetes, as part of CagriSema. In REIMAGINE 2, in 2,713 adults on metformin, CagriSema lowered HbA1c by 1.91 percentage points against 1.75 with semaglutide alone ^[14]. The diabetes medicines it would join are covered in type 2 diabetes medications.

So "what is cagrilintide peptide used for" has a narrower answer than many pages give. It is used in clinical trials. Outside them, people inject unregulated products sold under the name, and no trial describes those products. The regulatory path for the combination is tracked in the CagriSema approval timeline, and the drugs it would compete with are in new weight-loss drugs.

Weight. On its own, cagrilintide at 4.5 mg weekly produced more weight loss than daily liraglutide 3.0 mg in the phase 2 trial, 10.8% against 9.0% ^[2]. A 2026 meta-analysis of the placebo-controlled trials put the average difference from placebo at -6.08% of body weight for cagrilintide alone ^[17]. In the one head-to-head trial against tirzepatide, CagriSema produced 20.2% weight loss against 23.6% with tirzepatide 15 mg over 84 weeks under the treatment-regimen estimand and did not meet its primary endpoint ^[18]; see the tirzepatide record.

Blood pressure. The same meta-analysis found cagrilintide alone lowered blood pressure ^[17].

Blood sugar. Alone, cagrilintide did little for HbA1c: the meta-analysis found no meaningful improvement ^[17], and in the phase 2 diabetes trial HbA1c fell by 0.9 percentage points with cagrilintide against 2.2 with CagriSema ^[16]. The glucose benefit of the combination comes mostly from semaglutide; see the semaglutide record.

Not measured as benefits. No published cagrilintide trial has reported effects on muscle, energy, libido, longevity or athletic performance. Pages that list these as "cagrilintide peptide benefits" are not reporting trial results.

The searches "what does cagri peptide do for men" and "what is cagrilintide for men" ask a question the published evidence has not answered separately. No published cagrilintide trial reports its results split by sex in the abstracts this site has checked. What exists is the make-up of the trials, and in several of them men were the majority:

So the answer for men is the same answer as for everyone in the trials: cagrilintide reduced appetite and body weight through the amylin pathway, with gastrointestinal side effects as the main cost. Men were well represented, which means the overall results are not drawn mostly from women. Whether men lose a different amount than women on cagrilintide has not been published. No trial has studied effects on testosterone, fertility or muscle-building, and claims about those are not supported by any study on this page.

Cagrilintide is the most advanced of a wave of long-acting amylin drugs. The others differ mainly in how selectively they hit each receptor. Eli Lilly's eloralintide preferentially activates human AMY1R, 12-fold more than the calcitonin receptor, where cagrilintide activates both ^[20][7]. In lean rats, eloralintide caused significantly less conditioned taste avoidance, a laboratory proxy for nausea, than cagrilintide ^[20]. Whether that difference holds in people is not established, because the two have not been compared in a trial.

A 2026 network meta-analysis of six trials ranked high-dose subcutaneous amycretin first for weight loss against placebo (-23.95%), followed by high-dose eloralintide (-18.01%) and high-dose CagriSema (-17.18%), all ahead of semaglutide 2.4 mg (-11.45%) ^[21]. The authors called the data sparse and low in certainty ^[21]. The full class, including pramlintide and the newer agents, is in amylin analogs explained; Lilly's drug is in eloralintide vs cagrilintide. For the triple agonist people often ask about next, see the retatrutide record; cagrilintide and retatrutide have not been tested together in people.

• Approval. No regulator has approved cagrilintide or CagriSema. The FDA was expected to review the CagriSema application in 2026 ^[4]; this page will change when a decision is published.
• Cardiovascular outcomes. REDEFINE 3, the CagriSema cardiovascular-outcomes trial, is ongoing ^[4].
• Cagrilintide alone in phase 3. The RENEW trials have started; the 11.8% figure is from a sub-analysis of a CagriSema trial, not from a dedicated monotherapy trial ^[8].
• Results by sex, and long-term use. Not published; the longest completed trials ran 68 to 84 weeks ^[3][18].
• Anything sold outside trials. Product identity, purity and dose are unknown, so the trial results do not describe it.