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Weight loss injections/treatments

Discuss weight-loss injections and treatments, including personal experiences. Mumsnet hasn't checked the qualifications of anyone posting here. You may wish to speak to a medical professional before starting any treatments.

Mounjaro Local Injection Site Reaction

11 replies

Ashabeth · 08/04/2025 09:53

Hiya,
I've been really lucky to have minimal side effects on my MJ journey so far, however when I moved up to 5mg I started to get a reaction around my injection site. Redness and slight skin swelling that spreads outwards, with a bruise around the edge.
I'm now on week 5 of 5mg (second pen) and the reactions seem to be getting larger. I have tried injecting in my thigh as I was only using my stomach before and the reaction is just as angry.

I'm feeling fine in myself and my pharmacist has just told me to keep an eye on it.
I've read that it's quite common but just wondering if anyone on here has had experience of it and if its subsided or they've found a magic cure?

OP posts:
shrinkingthiswinter · 08/04/2025 10:09

I had this for a while and then it stopped. Wasn’t as bad as yours, though. Just red and itchy. Thigh was better.

northerneast · 08/04/2025 10:14

Did your pen come with different needles? I was given 0.25 x 5mm needles from med express and when I changed pharmacy I was sent 0.23 x 4mm. I know this sounds weird but I started feeling a little bit sore when doing my injection where previously I never felt it at all. I ordered some of the 0.25 x 5mm needles and started using them again and have not had any issues.

Icanthinkformyselfthanks · 08/04/2025 10:18

Use a longer needle and take antihistamine.

Ashabeth · 08/04/2025 10:19

Icanthinkformyselfthanks · 08/04/2025 10:18

Use a longer needle and take antihistamine.

Thank you. Do you take the antihistamine as the same time as doing the injection?

OP posts:
Ashabeth · 08/04/2025 10:20

northerneast · 08/04/2025 10:14

Did your pen come with different needles? I was given 0.25 x 5mm needles from med express and when I changed pharmacy I was sent 0.23 x 4mm. I know this sounds weird but I started feeling a little bit sore when doing my injection where previously I never felt it at all. I ordered some of the 0.25 x 5mm needles and started using them again and have not had any issues.

Thank you. I've only used the same sized needles but I have read that longer needles can help. I'll speak to the pharmacist about getting some longer, finer needles

OP posts:
Icanthinkformyselfthanks · 08/04/2025 10:21

Ashabeth · 08/04/2025 10:19

Thank you. Do you take the antihistamine as the same time as doing the injection?

Yes or preferably a bit before. It’s a local reaction so the longer, deeper needle should help. 😊

Arglefraster · 08/04/2025 19:21

I've had this for a few months but it's getting better now.
Couple of months without a reaction, then It was a small raised red patch for a couple of weeks then the reaction got bigger & lasted longer, then the reaction happened more quickly (6 hrs after jag cf 24-36hrs before) but same intensity/duration. It now seems to be reducing (6 months tx, 4 months reactions)

I've tried lots of things - longer needle, keeping skin cold after jag, systemic antihistamine, local analgesic/anti itch, hydrocortisone cream.

the only thing that actually seems to help me is hydrocortisone cream - putting it on the injection site regularly even before reaction shows.

good luck, hope it goes away quickly for you

Ashabeth · 08/04/2025 19:27

Thank you. I’ve read tonight that the needles are stainless steel and contain nickel. I am really allergic to nickel so that could be a contributing factor. I also react horribly to mosquito bites so I think my body just generally doesn’t like anything alien…
I’m not too concerned as I’m generally well in myself and it’s a minor inconvenience.
I’m going to try antihistamines and will use the hydrocortisone more regularly and hopefully my body will get used to it as a lot are saying the reactions stopped at a certain point… we will see!

OP posts:
raspberrymeringue · 08/04/2025 21:26

I had this for 2 months too. Mine seemed to be linked to two particular pens. I didn't find anti histamines helped. A little bit of hydrocortisone cream helped. Mine were very itchy, red and slightly swollen, almost like you would get from an insect bite.

IsItSnowing · 09/04/2025 08:37

I started getting this a couple of months ago after months without a problem. I get an itchy red circle about 12 hours after I inject. It goes down after about a week but I've got lots of circles on my stomach now where they've been. They go eventually though.
At least I know where not to inject the next week lol.
I take strong anti-histimines anyway but I've asked for longer needles with my next order to see if that helps.

BumbleBeegu · 09/04/2025 08:52

I had really awful reactions at the injection site once I moved up from 2.5mg. I ordered 8mm needles and all has been well since 👌🏻

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