Cagrilintide Side Effects: What the Phase 2 Trial Reported

By DoseGauge Editorial · Updated 2026-07-03 · 4 min read

Cagrilintide is investigational and not FDA-approved, so there is no agency-reviewed side-effect list with frequencies. What exists comes from clinical trials. In the Lancet phase 2 dose-finding trial, the most common side effects were gastrointestinal: nausea, vomiting, constipation, and reduced appetite, mostly mild to moderate and more likely at higher doses (Lau et al., 2021). There is no long-term human safety data, because the compound has not been studied in people over long periods. This page is informational and educational only, not medical advice, and it recommends no dose. For dosing, see the cagrilintide dosage guide.

What the trial reported

Because cagrilintide has no FDA label, its side-effect information comes from trial data rather than a prescribing document. The clearest source is the phase 2 dose-finding trial (Lau et al., Lancet 2021), which tracked adverse events across a range of once-weekly doses against placebo.

The pattern it found is the one seen across appetite-acting metabolic drugs: the side effects were mostly gastrointestinal. Nausea was the most commonly reported, along with vomiting, constipation, and reduced appetite. Most events were mild to moderate rather than severe, and they were dose-related, meaning they showed up more at the higher doses than the lower ones. That dose relationship is the reason the trial raised each arm to its target slowly instead of starting at the full dose.

Reduced appetite sits in an odd place on that list. For a weight-management compound it is part of the intended mechanism, not only a side effect: amylin agonists are thought to work partly by increasing the feeling of fullness. Whether a given person experiences that as a helpful effect or an unpleasant one is individual.

What is not known

The trial data describes short-term, dose-finding experience. It does not answer the longer questions.

There is no long-term human safety record for cagrilintide. It has not been studied in people over the multi-year periods that would reveal uncommon or delayed effects, and as an investigational compound it has no post-marketing surveillance behind it. The absence of that data is not the same as a clean safety record. It means the long-term profile is simply unknown.

There is also no established safety information for use outside a trial, including self-directed use of material bought as a research compound. Purity, identity, and dose accuracy are not guaranteed for such material, and those uncertainties sit on top of the compound's own unknowns. DoseGauge does not assess safety. The cagrilintide calculator only performs reconstitution and unit math on the numbers you enter, and whether the compound is appropriate for you is a question for a licensed clinician.

Frequently asked questions

What are the side effects of cagrilintide?

In the phase 2 trial, the most common side effects were gastrointestinal: nausea, vomiting, constipation, and reduced appetite (Lau et al., 2021). They were mostly mild to moderate and more common at higher doses. Because cagrilintide is not FDA-approved, there is no agency-reviewed list with frequencies, and there is no long-term human safety data.

How does cagrilintide make you feel?

The most commonly reported experiences in the trial were gastrointestinal, especially nausea, plus a reduced appetite that is part of how amylin agonists are thought to work. Effects were mostly mild to moderate and varied between people. This is a description of trial reports, not a prediction of how any individual would feel.

Is cagrilintide safe?

This page cannot call it safe. Cagrilintide is investigational, is not FDA-approved, and has no long-term human safety data. Its known side effects from trials are mostly gastrointestinal, but uncharacterized long-term risk is not the same as low risk. Whether it is appropriate for a specific person is a clinical question for a licensed clinician.

How long does cagrilintide stay in your system?

Its half-life is roughly 7 days (about 159 to 195 hours), which supports once-weekly dosing (Kruse et al., 2021). As a rough guide, a drug is largely cleared after about five half-lives, so cagrilintide would take on the order of five weeks to leave the system after the last dose. Steady state during regular dosing builds over about 5 to 6 weeks.

Informational and educational only. Not medical advice. DoseGauge computes from the values you enter and does not recommend a dose. Talk to a licensed clinician before using any peptide or GLP-1 medication.