What the label says is common
The label is useful here because it shows scale. In adult Wegovy trials, nausea, diarrhea, vomiting, constipation, and abdominal pain were all reported commonly, and the label says gastrointestinal reactions were reported most often during dosage escalation.
Some reactions are common early in treatment, but symptoms that stay severe, keep coming back, or start disrupting eating, drinking, or daily function should not be brushed off.
When the reaction needs faster attention
MedlinePlus and the labels are the right place to get more serious warning language. Ongoing severe stomach pain, repeated vomiting, inability to keep fluids down, symptoms of dehydration, or sudden vision changes are not the same as mild, early nausea.
That is the practical line to watch: mild early nausea on one side, repeated vomiting, dehydration, severe abdominal pain, or sudden vision symptoms on the other.
What to write down first
Before trying to summarize the event for anyone else, write down the medication, when you started, how the dose changed, when the symptoms began, whether you saw a doctor, and whether you stopped the medication.
If the problem is mainly GI, go deeper on the gastroparesis page. If it is mainly vision, use the retinopathy page. The process page explains what information is most useful in an initial inquiry.