Get upper-right belly pain checked by a clinician instead of guessing at the cause.
What the NHS flags
On its tirzepatide page, the NHS names gallstones or swelling of the gallbladder (cholecystitis), which can cause severe tummy pain. That is the link behind the question in the title.
Gallstones are one cause the NHS names. Only a clinician can say whether that is what is happening to you.
Reading the medicine's own information
The NHS page on tirzepatide and the MedlinePlus entry for tirzepatide injection are the places to read a medicine's side effects in full. For wider background, the CDC's obesity overview and the Cleveland Clinic's explainer on weight control and obesity are plain reads.
Calling a clinician about the pain
Contact your prescriber or another clinician about the pain, and say which GLP-1 medicine you take. Do not wait for the pain to explain itself.