Who should not take a GLP-1 medication?

There are two separate lists. The FDA label carries the absolute contraindications, which are short. The clinical list is longer, and it is the one most consumer prescribing services never discuss. Both matter, and a five minute intake questionnaire will not surface the second list.

The absolute contraindications on the label

Both the Wegovy and Zepbound labels contraindicate the drug in patients with a personal or family history of medullary thyroid carcinoma, and in patients with multiple endocrine neoplasia syndrome type 2. Both contraindicate use after a serious hypersensitivity reaction to the drug or its excipients. Family history means a parent, sibling or child, and it is worth actually asking your relatives rather than assuming. Pregnancy is the third: the labels instruct that the drug be stopped when pregnancy is recognised, and the Wegovy label advises stopping at least two months before a planned pregnancy.

The clinical reasons a specialist says no or not yet

An active eating disorder with restriction or purging is the one I decline most often. A drug that removes hunger can be used to serve the disorder rather than the person, and there is no trial evidence supporting its use in that setting. Established gastroparesis, severe gastro-oesophageal reflux and prior bowel obstruction are all reasons to reconsider, because the entire mechanism is delayed gastric emptying. A history of acute pancreatitis is a caution rather than an absolute bar: a Cleveland Clinic review found that 10 percent of patients with prior pancreatitis had a recurrence on GLP-1 therapy, and more than half of those episodes had another cause. That is a conversation, not an automatic refusal.

When something else should be treated first

Untreated hypothyroidism, Cushing syndrome, obstructive sleep apnoea and weight-promoting medications all cause weight gain that a GLP-1 will partly mask without addressing. The 2015 Endocrine Society guideline recommends screening for secondary causes when the history or examination suggests them, and recommends substituting weight-neutral alternatives for weight-promoting antipsychotics, antidepressants, antiepileptics and beta blockers where that is clinically possible. Starting a GLP-1 on top of an untreated driver is not wrong, but it is incomplete.

Bring three things to the consultation that decides this: a full family history of thyroid cancer, a complete medication list including anything prescribed by psychiatry, and an honest account of your eating pattern including any history of restricting or purging. Those three items change the answer more often than your BMI does.