Discuss possible harms before care

Begin with the stomach effects

The Wegovy (semaglutide) label is its official medicine information. The version reviewed September 26, 2026 lists nausea, diarrhea, vomiting and constipation among common side effects.

Nausea means feeling sick to your stomach. In the weight-management injection trials summarized in that label, nausea occurred in 44% on Wegovy and 16% on a dummy injection.

These are trial figures for that product, not a forecast for you or every semaglutide form.

The label also describes severe stomach problems and kidney injury associated with fluid loss from vomiting or diarrhea.

Make room for family history and allergies

Semaglutide labels carry a boxed warning, the FDA’s strongest label warning, about thyroid tumors. FDA is the US Food and Drug Administration.

The tumors appeared in rats and mice. The labels say it remains unknown whether semaglutide causes these tumors in people.

The labels say not to use semaglutide if you or someone in your family has had one particular, rare type of thyroid cancer: medullary thyroid cancer, also called MTC.

If you only know that a relative had thyroid cancer, ask the clinician to check which type it was. Do not assume that every thyroid cancer is MTC.

The labels also say not to use semaglutide if you have MEN 2, the medical name of a rare inherited illness.

Tell the clinician if that illness has been diagnosed in your family. If you do not know its name, ask the clinician to help check your family’s medical records.

They also exclude a past serious allergy to semaglutide or its other ingredients.

These label facts were reviewed September 26, 2026. Bring the relevant history to the clinician rather than trying to settle suitability from a checklist.

Know when help is urgent

The US National Library of Medicine publishes the MedlinePlus health guide, which describes a severe allergic reaction as a life-threatening emergency.

It lists a swollen face or tongue and trouble breathing or swallowing as possible signs, and tells people with severe symptoms to get emergency help.

Seek emergency help for severe symptoms of an allergic reaction.

Reading for this question

• Wegovy (semaglutide) label

  Read the common effects and the serious concerns together. A clinician can relate them to your history.

• MedlinePlus on severe allergic reactions

  Emergency signs belong to an urgent-help plan, not a self-diagnosis test.