CommunitySide Effects

Allergic reaction or Lipohypertrophy?

7 replies4 peopleNov 4, 2025☆ Follow
Summary

Worsening itchy welts at retatrutide injection sites - allergy or lipohypertrophy and what to do?

Participants describe localized reactions that can appear months into use and may stem from immune response or shallow injection technique. Suggestions include trying a half-inch needle for shallow intramuscular delivery in the shoulder, applying flonase topically, ensuring a 90-degree angle, or switching peptides if reactions spread. Most note that continuing often leads to resolution after several months while serious systemic effects warrant immediate change.

What this discussion establishesStill open

Whether shallow intramuscular shoulder injections remain safe and effective long term for this user

Nothing here is advice.

7 replies · 4 people
GreenLedger90archiveopening postNov 4, 2025

I've been on this medication since May of last year. Family members using identical batches have had zero issues. Starting in August I developed itchy welts that grow from quarter size up to half a tennis ball and stick around roughly three days. Stomach injections with spacing still led to worsening reactions and the same thing happened in my thigh. I assumed it was fat buildup until the thigh swelled despite no injections there for a month. This feels like an allergy. Has anyone else run into it and should I consider a different source or switch to tirzepatide?

AmberLantern21archiveNov 4, 2025

This issue popped up for me with one version and for my spouse with the other. We found that inserting a longer needle into the upper arm area avoided part of the body's defense reaction. Wiping the spot with a certain spray both right before and right after the shot also helped. Moving to another version usually clears it up without fail though it is not the first choice. Folks who keep going through it often notice the problem fades after a couple months once it shows up. If the response spreads and causes welts in spots away from where the shot went in then switching versions is what we did.

GreenLedger90archiveNov 5, 2025
↳ replying to @AmberLantern21

I appreciate you getting back to me. This really clarifies things. Does that mean the shot in the shoulder goes straight into the muscle?

AmberLantern21archiveNov 5, 2025
↳ replying to @GreenLedger90

Half an inch is enough for a very shallow IM for most people.

AmberLantern21archiveNov 5, 2025
↳ replying to @GreenLedger90

It is definitely effective both for the medication and usually for preventing the reaction you described. Safe is something you decide. Using unregulated drugs is already past most people's idea of safe. You are deliberately bypassing part of the immune system. Are your antiseptic steps solid? How do you feel about filtering?

SlowLantern99archiveNov 5, 2025

Tirzepatide trials showed a percentage of people developed an allergy over time so it would not surprise me if the same occurs with reta and other GLP drugs. At the same time none of those reactions were serious or severe enough to require any warning label as far as I recall.

BlueWillow27archiveNov 5, 2025

Welts and itchiness might simply mean you are not going deep enough or using too much of an angle so the medication ends up between skin layers instead of subcutaneous. That happened to me on both tirzepatide and reta and the swelling plus itch lasted a day or two. If angle could be the cause try pinning closer to ninety degrees before moving to a longer needle. This is actually a good spot to get in-person guidance from a doctor, PA, nurse or pharmacist who can check your technique directly.

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Allergic reaction or Lipohypertrophy? · ZyraTrack Community