Mounjaro/Wegovy severe allergic reaction

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Hi,

I had a severe allergic reaction after taking my 2nd starter dose of Mounjaro this week. Took the injection on Sunday afternoon (I was absolutely fine after first dose the week before). I woke up on Wednesday with hives/urticaria rash down my arms so took antihistamine. Woke up at 3am on Thursday with the left side of my face badly swollen and the hives worse. I looked like I’d been beaten up. I’m now on a 5 day course of steroids, different antihistamines and a course of flucloxacillin to cover all bases. After researching, I found that Mounjaro does have Anjioedeme as a side effect.

i have previously taken Wegovy for 4 weeks without any allergic reaction, i stopped taking it as I felt nauseous a lot of the time, then after 4 months decided to try Mounjaro.

has anyone had a similar reaction? Would I now be likely to experience another allergic reaction if I switch back to Wegovy?

Sorry, can't advise about WLI specifically but about 4 years ago, I had anaphalactic reaction after a flu jab which I'd had every year for more than 10 years with no issue. I was advised to never have it again as it would just get worse. The fact that the reaction was delayed by about 36hours, and not immediate, was a more worrying aspect apparently. I wouldn't risk it again without doing a lot of research and speaking to GP or prescriber tbh.

I think I'm also not taking very well to mounjaro. Previously took ozempic for a number of months without a problem and I'm considering going back. I'm on dose 3 of the first pen of mounjaro. My first two doses caused rather big injection site reactions but the third dose I took on Friday has caused full blown case of hives from my neck to calves.

I think I'll probably leave it a few weeks to clear my system then give the other drug a go again

Hope you’re ok! I contacted the pharmacist from the online pharmacy I used, she said people can be allergic to benzoyl alcohol which is in the mounjaro pen, it’s not used in Wegovy, not sure about ozempic. I have taken my final steroids today, and will keep taking antihistamines just in case I think!

Sorry to hear that, I hope it gets better for you now.

Have you done a yellow card report?
https://yellowcard.mhra.gov.uk

Sound like the sort of thing that ought to be reported.

I’ve not done one as I can’t be sure that it was mounjaro that caused the reaction, the hives started 3.5days after 2nd injection, and then the face swelling the day after the hives. The GP said it could have been absolutely anything within that time frame.

Hi I had an allergic reaction to mounjaro loading dose first one
couldn’t swallow and next day my neck arms throat all were agony and swollen lymph node in my neck and I was in lots pain
saw a pharmist face to face appointment today 7 weeks later and he said if you have any swelling in our throat area you can’t have any weight lose jabs

really sad so Bach to struggling

Sorry to hear that, hope you’re ok. I spoke to my prescribing pharmacist again, she said it would have been mounjaro that caused my reaction, even though it happened 3.5days after my injection.

I was able to try wegovy and have taken it for 4 months now, I’ve taken a daily antihistamine along with it and have been fine - weight loss has been almost non existent though so I’m discontinuing after my current pen.

My husband had exactly the same reaction after the second dose. Injected friday, hives within 3 days and face swelling day 4. So bad that he needed to go to a & e. 3 days later and he still has swollen eyes but airway clear

If it is the pen which could still be an issue if you try Wegovy what about Rybelsus which is the tablet form of semaglutide?

You should report it anyway. The idea of the yellow card system is that everyone taking a medication reports every single unusual symptom or side effect that happens afterwards, even when they can't know for sure the medication caused them. Then it's the scientists who look for patterns to try to work out whether that medication is likely to have caused particular things that turn up more often than expected, or whether it's probably coincidence - you're not meant to try to do that working out yourself. You just provide one extra count of that type of symptom happening after someone takes that medication, to go into their stats.