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Motsc reaction

33 replies20 peopleMay 25, 2026☆ Follow
Summary

what kinds of reactions do people report with MOTS-C and what should you do if one happens

Multiple users describe sudden hives, welts, intense itching, dry heaving, dizziness, heart pounding, and even collapse after injections, sometimes only after restarting following a break. Several conclude these are allergic or immune responses that can appear locally at first then turn systemic, and they advise stopping permanently if anything like that occurs. A few tried lowering the dose or switching to nasal but most who reacted strongly decided against continuing. One separate report of back pain after microdosing another peptide was later ruled unrelated by medical tests.

What this discussion establishesWhere people disagree

whether MOTS-C is generally safe enough to try with basic precautions or inherently risky enough that stories of reactions should deter everyone

Still open

exact cause of the reactions and whether they are tied to specific batches, fillers, or cumulative immune sensitization

Nothing here is advice.

33 replies · 20 people
SteadyMarble16archiveopening postMay 25

I am on a second round of this and after the second-to-last shot from a 10 mg vial at 2.5 mg I started dry heaving violently for several minutes right after rubbing the area. I got very hot and the injection site developed several raised hive-like bumps. Once the heaving stopped I took a 10 mg antihistamine, sat down, and began feeling better; the hives disappeared and even the usual red itchy lump I normally get for a day was gone. It was pretty startling. Has anyone gone through something like this?

ClearBeacon24archiveMay 25
↳ replying to @SteadyMarble16 (opening post)

Only happened to me with muscle shots, subq was usually fine. Sounds like you might have hit a vein.

SteadyMarble16archiveMay 25
↳ replying to @ClearBeacon24

I doubt it because it was in the belly area, though I guess it could still be possible.

CopperAlder51archiveMay 25
↳ replying to @SteadyMarble16 (opening post)

There are reports of severe allergic reactions to this compound, either right away or building gradually with continued use. Yours sounds like one of those and your body is signaling to stop. Even though the main reaction was at the site, the heaving and hives show it went systemic. I would not use it again.

SteadyQuill55archiveMay 25

I just do not see this one as nearly always harmless the way many other peptides are viewed. It is popular and I am not trying to ruin anyone's experience, but enough people have had sudden and really rough days after trying it that I think the safety steps should start with having someone nearby who can call for help if needed.

WarmSparrow96archiveMay 26

I went through almost the same thing. Finished several vials without trouble, took two months off, then started again with a new vial at the same dose. Right away I got a strong histamine response with bad hives and itching across both sides of my abdomen that took hours to fade. Dropping the dose helped a bit but did not stop it completely. There was a recent video explaining that with some peptides the immune system can build tolerance while you are using them steadily, but after a break the response comes back stronger on restart. The suggestion was to begin lower and slowly increase, but if my body is reacting that way I am not going to keep forcing it. This compound is done for me.

SteadySparrow49archiveMay 26

Two weekends back I ended up on the floor after the last 2 mg from the final vial of the last box. Right after the shot I felt the need to use the bathroom because my gut felt like it was about to empty out. While on the toilet my heart started racing, hands and upper body went tingly, and I tried to reach my office across the hall to lie down. I did not make it to the bedroom, collapsed on the floor, and stayed there ten to fifteen minutes. My watch showed Afib that night. It was intense. This was on a Friday, and the Monday before that I had a bad skin reaction to the same thing. Everyone should be careful.

WryQuill22archiveMay 26
↳ replying to @SteadyMarble16 (opening post)

What the previous reply said. Most users probably handle it without issue, but from what I have seen the reactions reported so far all came after injecting it.

ClearWillow59archiveMay 26

Someone mentioned an alternative to an epipen that might be easier to use. You should look into that before trying another shot, but I would actually recommend not using it again at all. If you do have a serious reaction get to the ER because any countermeasure might not last long enough.

GreyAlder39archiveMay 26
↳ replying to @SteadySparrow49

What you described sounds a lot like a vagal response after the injection. I have had similar episodes from another medication. My doctor advised not to stand, wait it out, and raise the legs if possible. Any atrial fibrillation episode should be checked by a cardiologist.

SharpHarbour71archiveMay 26
↳ replying to @SteadyMarble16 (opening post)

This is exactly why I will never try it. I have heard too many accounts of people suddenly getting severe allergic reactions out of nowhere.

CopperSignal27archiveMay 27

If there is any realistic chance this was a systemic allergic reaction, and it seems plausible, the only safe choice is to stop. Even a small or uncertain risk of anaphylaxis is not worth taking. This compound appears quite immunogenic given how often people get local site reactions, so broader reactions would not be surprising. There is little clinical trial data available, mostly just forum reports, but better to be cautious.

BrightBeacon35archiveMay 27

I used 10 mg three times a week. No problems, but also no noticeable effects. You all who get benefits are the lucky ones. Still, if your body is warning you off, listen to it.

AmberCompass48archiveMay 27

that stuff grosses me out but might taste great to someone else 😅😅😅😅😅😅😅😅😅😅🤪

ClearQuill84archiveMay 27

This thread has me thinking. I have a full kit sitting in the freezer and was planning to start in about two weeks. On the other hand twenty or thirty years ago I was reckless enough to inject underground steroids probably made in some basement next to a coal pile and I am still here.

PatientTimber45archiveMay 27
↳ replying to @BrightBeacon35

I tried it and got the golf-ball-sized lumps with it. I would not call that luck.

PatientTimber45archiveMay 27
↳ replying to @ClearQuill84

Just start with 1 mg. Do not jump to 2.5 or 5 mg. For me everything went wrong once I went to 2.5 mg and higher.

ClearQuill84archiveMay 27
↳ replying to @PatientTimber45

Did you pin every other day or follow a five-days-on two-days-off schedule?

BrightSignal52archiveMay 27

Has anyone heard of reactions from using it nasally? Worried about skin reactions I tried that route instead. My first supply came in a nasal bottle and I noticed effects right away so I kept going with it.

CopperAlder51archiveMay 27
↳ replying to @BrightSignal52

This molecule is around 2174 Da, roughly twice the size that usually crosses the blood-brain barrier well. Whatever effect you are feeling is probably only the small portion absorbed through the mucosa before most of it gets broken down by enzymes. You are likely getting just a fraction of the sprayed amount.

WarmAlder42archiveMay 27
↳ replying to @ClearQuill84

Same situation here. Full kit in the freezer but I will probably never use it. I can handle occasional welts and itching from another peptide because the benefits are clear, but this one seems too unpredictable for the uncertain payoff. I do not want to risk a reaction for something that might not even help measurably.

ClearQuill84archiveMay 27
↳ replying to @WarmAlder42

Fortune favors the brave. But I understand your view.

BrightSignal52archiveMay 27
↳ replying to @CopperAlder51

True, it is less efficient, but it is working so far and I have had no skin reaction or worse.

SlowLedger21archiveMay 27

Yikes. I take 500 mcg with no trouble. I recently started microdosing another compound and right after the first 0.5 mg shot I got sudden pain in my right lower back that lasted three days. When I tried again four days later the same pain returned. That worried me enough to search forums and found someone else who ended up in the ER with identical symptoms and was told it was kidney swelling from blocked urine flow. I am sitting in urgent care now getting urine and blood tests plus an ultrasound. The doctor does not think it is connected but the timing makes me wonder.

SlowLedger21archiveMay 27

Yes, just a microdose. I wondered if something else caused it so I tried again and the pain came back. Strange, right?

SteadyAnchor31archiveJun 9
↳ replying to @SlowLedger21

I had the same kind of reaction after the fourth daily 250 mcg of a different peptide combo. First time nothing, second time a slight tingle in my lower back that I ignored, third time a dull ache that faded quickly, fourth time the ache stayed and took hours to ease. I was not dehydrated and had slept fine. I am starting to suspect it might be poor-quality filler rather than the active ingredients. I will not be repeating it.

CopperSignal27archiveJun 9
↳ replying to @SlowLedger21

This is odd. I am trying hard to figure out how that compound could cause one-sided lower back pain right after two separate injections and cannot come up with a plausible mechanism. Just because neither I nor the ER doctor can explain it does not automatically make it harmless though. Since it happened twice it is worth getting checked, which it sounds like you are doing. I also cannot see how it would cause kidney swelling from outflow blockage, which is usually from stones or tumors. The things that could theoretically be involved are all very unlikely, but the pattern is unusual. One possibility is the product was not what it was labeled, though it is hard to imagine other common peptides causing this either. Another is a reaction to something in the product or the water used to mix it.

SlowLedger21archiveJun 9
↳ replying to @CopperSignal27

Thanks for the comment. It definitely was not the mixing water because I used the same brand I use with everything else without issue. The tests ruled out kidney swelling. I think it may have been the fillers so I stopped after the second shot. I am trying to lose about ten stubborn pounds and nothing else has worked. It did drop two pounds a week after the second shot before I quit. I filtered it too, so I have no idea what caused it, maybe endotoxins. I will report back if I try a different batch.

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