GLP-1 injections such as Mounjaro, Ozempic and Wegovy are among the best studied medicines of the last decade, and most people tolerate them well. They still have side effects, a few genuine exclusions, and one or two risks that deserve respect. Here is the honest picture: what is common and manageable, what is rare and serious, and who should not take these medicines at all.
At the clinic: Dr. Fehmida prescribes tirzepatide (Mounjaro) and semaglutide only after screening for everything on this page, as part of the clinic’s supervised peptide programmes in Clifton, Karachi.
The common side effects
Nausea is the headline one, usually mild, worst in the first weeks and around dose increases, and it settles for most people. Constipation or diarrhoea, burping, reflux and a reduced appetite for rich or fatty food are also common. These effects are dose related, which is exactly why proper treatment starts at a low dose and climbs slowly. Most patients who quit in the first month were started too high or escalated too fast.
How a good programme minimises them
Slow titration on a published schedule. Smaller meals, more protein, less fried food in the early weeks. Plenty of water, and fibre for constipation. Reviewing symptoms before each dose increase rather than climbing on autopilot. None of this is complicated, but it is the difference between a rough first month and a smooth one, and it is what supervision is for.
The rare but serious ones
Pancreatitis is rare but real: severe, persistent upper abdominal pain needs same day medical attention. Gallbladder problems can occur, partly because rapid weight loss itself raises that risk. Dehydration from vomiting can strain the kidneys. And anyone on diabetes medicines such as insulin or sulfonylureas needs doses coordinated, because adding a GLP-1 can drop blood sugar too far.
Who should not take GLP-1 medicines
A personal or family history of medullary thyroid cancer or MEN2 syndrome rules these medicines out. So does a history of pancreatitis, and pregnancy or breastfeeding; anyone planning pregnancy needs to stop well in advance. Severe gastroparesis, significant eating disorder history and some gallbladder conditions also call for caution. None of this shows up without asking, which is why a questionnaire and consultation come before any prescription at the clinic.
The side effect nobody screens for: muscle loss
Lose weight fast without enough protein or resistance training and a meaningful share of the loss is muscle. That slows your metabolism and makes regain more likely. A supervised programme tracks more than the number on the scale and protects muscle with nutrition targets and training guidance from day one.
Common questions
Do the side effects go away?
For most people, yes. Nausea and digestive effects fade as the body adapts, typically within weeks of each dose step.
Can I just stop if I feel unwell?
Tell your doctor first. Many issues are fixed by holding the dose or slowing the climb rather than abandoning treatment.
Are injections bought online safe?
Unverified sellers mean unverified storage, authenticity and dosing, with nobody screening you for the exclusions above. That is where most horror stories start.
How do I know if I am a candidate?
Book an assessment. Screening takes one consultation, and you will get a straight answer either way.
This article is educational and does not replace medical advice. Brand names are referenced for identification only. Treatment decisions are made only after an in-person consultation.
Consultant Dermatologist and Laser Skin Specialist, MBBS, MCPS. Over 35 years in dermatology, five of them in Zurich, practising in Clifton, Karachi since 1999.
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