What is known about side effects?

Stomach problems were common with CagriSema

In REDEFINE 1, the journal reported stomach or bowel problems in about 80 of every 100 people on CagriSema. With placebo, a shot without the study drug, about 40 of every 100 people had those problems.Read the journal report

Most of those problems were mild or moderate and did not last.

These findings included feeling sick, vomiting, and constipation, which means trouble passing stool.

Ask how the person treating you would respond to a problem and how to reach them between visits.

The earlier cagrilintide-only study also found stomach trouble

In the earlier 26-week study, The Lancet reported stomach or bowel problems in 41 to 63 of every 100 people on cagrilintide. For placebo, the figure was 32 in every 100 people.Read the cagrilintide-only study

Different strengths gave different rates within that range. Problems where the needle entered the skin were also common in that study.

The recorded study summary does not say which problems happened at that spot. Ask what those reactions were and how serious they were.

These are findings from a study. They do not tell you what is inside a product offered online.

Official warnings are still missing

A medicine's label is its official information about use and warnings.

As of September 28, 2026, neither cagrilintide nor CagriSema had a Food and Drug Administration (FDA)-approved label.

There was therefore no FDA-reviewed list for either product covering pregnancy, medicine combinations, or who must avoid it.

Semaglutide (Wegovy, Ozempic) has its own label warnings; they do not establish what a future CagriSema label will say.

A severe allergic reaction needs emergency help

The US National Library of Medicine's MedlinePlus says severe allergic reactions threaten life and can develop quickly.Read the emergency guidance

Possible signs of a severe allergic reaction include difficulty breathing or swallowing, swelling in the face or tongue, and collapse.

If an allergic reaction causes severe symptoms, call 911 now or go straight to the nearest emergency room.