Anyone suddenly become intolerant to Tirz overnight?

[Mara_aa]

After 5 weeks at 3 mg, everything happened all at once, as if I had injected 30 mg instead of 3 mg. Same vial, NO dosing mistake, no math crimes committed.

My stomach basically factory-reset itself. I got hit with nausea unlike anything I’ve ever experienced, extreme weakness, and a general feeling of absolute doom.

For the last 10 days I’ve barely been able to stand upright. Minimal movement gives me shortness of breath and tachycardia, like I’m training for the Olympics every time I walk to the kitchen. Blood sugar low-ish (not dangerously low), blood pressure also low.

To make things even weirder, I simultaneously caught a monster cold and ended up taking antivirals for suspected shingles/herpes zoster because I had this horrible “needles in the skin” sensation.
Except… no rash. No blisters. Nothing. So apparently even my possible shingles wanted to stay mysterious and dramatic.

Doctor basically shrugged and told me to skip last Thursday’s dose. Bloodwork results arrive May 20th.

Today Shotsy estimates my level at 1.48 mg and I’m slightly better, meaning I’ve upgraded from “barely functioning houseplant” to “weak but technically alive.” I still barely eat or drink though.

My current fear is that I somehow became suddenly and permanently intolerant to Tirz overnight. I can’t really find stories similar to this, so I’m wondering: has anyone experienced a sudden hypersensitivity/reaction like this after previously tolerating the dose just fine? Any theories, experiences, or reassuring stories welcome.

For context: I’ve always struggled a LOT with Tirz and was actually close to quitting completely. Then, thanks to you guys, I discovered microdosing, which made things much more manageable.
That said, it has never really been an “easy” medication for me, but the results were worth tolerating a bit of suffering.

 

[CandyCap]

The tingling, painful skin can be side effects of both Tirz and Reta.....but seems to be more prevalent with Reta. It almost sounds like a Reta OD. You say you are positive it is the same vial/dosing etc? You have not added anything else new?

 

[Ascojoerg]

Yes, this happened to me last summer while on regular prescription Mounjaro. The day after injektion, suddenly nausea like never before, and just very bad diarrhea. It was a struggle to even stay hydrated due to the nausea, forget trying to eat anything for a week. I was at a higher dose (7,5mg) but I had been at that dose for 5 weeks and it was the same pen as the 2 weeks prior.

Good news is that it is not permanent (only from personal experience), I did stop cold as I was very scared of it happening again, so I stayed off for about 4 months. Then got curious about grey and started again just on low dose (Tirz 2,5mg) for maintenance and help with food noise. After a while on low dose, I decided to increase as I never got to my goal weight and was still obese. I have now lost an additional 5kg since slowly tritating up.

 

[5byfive]

I know you said no dosing mistake, but boy does it sound like a dosing mistake. You hear lots of stories about dosing mistakes and none about sudden intolerance issues. I've been absolutely sure of things in the past and been wrong befote. Plenty of people have talked about forgetting they had taken it and taking it again or just totally drawing the wrong amount. If it were me and it was working well, I'd probably wait till I was feeling better then start again at a slightly dose and see what happens.

 

[desinr-gal]

Anti virals are no picnic either.. which did you start first?

 

[WLBLD]

I know you mentioned not a new vial, but maybe now its built up in your system? Is it a new kit from a different vendor you haven't used before? I heard some people have sides on some vs others.

 

[sheilarae74]

I have been going through the exact same thing with reta over the past 10 days. I titrated up to 5mg 2 weeks ago and a few days later, I started feeling nauseous and haven't felt like doing anything all week. Malaise I guess they call it. I have had to force myself to eat. I have never felt this way the whole 17 weeks I have been on it. I ramped up my hydration because I thought it was that at first and and that is usually how I feel when I am dehydrated. So I loaded up on hydration drinks and ate so much damn salt my hands are puffy. I stopped taking all of my supplements except magnesium and potassium since last week, even stopping the GHK-cu this weekend and I still feel crappy.
I started my new kit a month ago and the first two weeks I felt almost nothing, so that is why I titrated up in the first place.
I feel slightly better today but I think once I stop feeling this way I am going to try to split up my dose and take 2.5mg every 3.5 days and see if that helps.

 

[Mara_aa]

The tingling, painful skin can be side effects of both Tirz and Reta.....but seems to be more prevalent with Reta. It almost sounds like a Reta OD. You say you are positive it is the same vial/dosing etc? You have not added anything else new?

Yes, I’m positive: same vial, same concentration, same dosing routine, and I’m sure I didn’t make a dosing mistake.

I haven’t added Reta or any other new peptide. Nothing new at all, except the antivirals, but those were started only after the skin symptoms had already appeared because my doctor suspected shingles/herpes zoster.

I actually knew about the “needle skin” sensation with Reta, but not with Tirz. Now I’m starting to wonder whether that was Tirz too. The strange thing is that it only happened on my left side, which is why shingles/herpes zoster was suspected in the first place (because it wasn’t bilateral).

I was definitely dealing with a pretty bad cold and a period of intense stress, but the reaction still felt completely disproportionate.

That’s why I’m so confused, it really felt like an overdose, but I can’t find any practical explanation for one.

 

[Mara_aa]

Yes, this happened to me last summer while on regular prescription Mounjaro. The day after injektion, suddenly nausea like never before, and just very bad diarrhea. It was a struggle to even stay hydrated due to the nausea, forget trying to eat anything for a week. I was at a higher dose (7,5mg) but I had been at that dose for 5 weeks and it was the same pen as the 2 weeks prior.

Good news is that it is not permanent (only from personal experience), I did stop cold as I was very scared of it happening again, so I stayed off for about 4 months. Then got curious about grey and started again just on low dose (Tirz 2,5mg) for maintenance and help with food noise. After a while on low dose, I decided to increase as I never got to my goal weight and was still obese. I have now lost an additional 5kg since slowly tritating up.

Thank you so much for this reply, this is incredibly reassuring to read right now.

What scared me the most was exactly the fact that it happened after weeks at the same stable dose.

Your description sounds VERY similar, except I got more nausea/weakness than diarrhea. The “can barely stay hydrated” part especially is exactly what I’ve been experiencing.

And thank you for mentioning that it was not permanent for you. Right now my brain is catastrophizing a bit and convincing me that my body has suddenly decided Tirz is poison forever…
Today is already day 12 for me and the improvements are still very mild, so at the moment the idea of taking another dose is absolutely not happening 😂

Have you ever considered trying Reta instead? I honestly can’t imagine going back to my old level of food noise long term.

I’m really happy you managed to restart successfully and even continue losing weight by titrating slowly again.

 

[Mara_aa]

I know you said no dosing mistake, but boy does it sound like a dosing mistake. You hear lots of stories about dosing mistakes and none about sudden intolerance issues. I've been absolutely sure of things in the past and been wrong befote. Plenty of people have talked about forgetting they had taken it and taking it again or just totally drawing the wrong amount. If it were me and it was working well, I'd probably wait till I was feeling better then start again at a slightly dose and see what happens.

Honestly, I completely understand why you’d think that, if I were reading this from the outside, I’d probably suspect a dosing mistake too 😅

That’s also why this whole situation has been so confusing for me: the symptoms felt almost like an overdose. And I keep wondering whether it could even be some kind of accumulation effect; at this point, I don’t know what to think anymore.

I checked the dose very carefully, I’ve always been extremely cautious with Tirz because I tend to react strongly to it. I’m almost overly careful with dosing because of the side effects I’ve had in the past; if I’m even one click unsure, I’d rather throw everything away than risk ending up with a much rougher week than usual.

Your suggestion does make sense. I genuinely want to continue, it has changed my life, and I really felt like I had finally found some balance with my food noise. So when I start again I’ll follow your advice and begin at a lower dose, taking things very slowly. I just hope I haven’t become intolerant to it.

 

[Mara_aa]

Anti virals are no picnic either.. which did you start first?

The Tirz reaction/symptoms definitely started first. The antivirals were started a few days later because of the suspected shingles/herpes zoster situation.

And yes, antivirals can also be rough, which honestly makes the whole thing even more confusing to untangle 😭

 

[Mara_aa]

I know you mentioned not a new vial, but maybe now its built up in your system? Is it a new kit from a different vendor you haven't used before? I heard some people have sides on some vs others.

Honestly, the build-up/accumulation theory genuinely makes the most sense to me right now, especially combined with stress and being sick at the same time.

And no, it wasn’t a new vendor or a new batch. Same source I had already been using and tolerating before this happened.

What really threw me off is that the reaction felt so sudden and disproportionate compared to my “usual” Tirz side effects.

 

[Ascojoerg]

Have you ever considered trying Reta instead? I honestly can’t imagine going back to my old level of food noise long term.

I have, and to be honest I have no good reason for not trying it other than I had already purchased a few kits of Tirz. I will probably take another look once I run out or cant hit my goal weight.

 

[DragonOfTheSea]

I actually knew about the “needle skin” sensation with Reta, but not with Tirz. Now I’m starting to wonder whether that was Tirz too. The strange thing is that it only happened on my left side, which is why shingles/herpes zoster was suspected in the first place (because it wasn’t bilateral).

The needles/sunburn "allodynia" definitely does not need to be bilateral for it to be from the Tirz (or from Reta). I've experienced it on both peptides, and presents wherever it wants- I've had it: around ankles, tops of the feet, upper thighs, glutes, back, stomach, even my cheek/face (only the right side). I would pin it (pun intended) on the Tirz before shingles.

 

[Mara_aa]

I have been going through the exact same thing with reta over the past 10 days. I titrated up to 5mg 2 weeks ago and a few days later, I started feeling nauseous and haven't felt like doing anything all week. Malaise I guess they call it. I have had to force myself to eat. I have never felt this way the whole 17 weeks I have been on it. I ramped up my hydration because I thought it was that at first and and that is usually how I feel when I am dehydrated. So I loaded up on hydration drinks and ate so much damn salt my hands are puffy. I stopped taking all of my supplements except magnesium and potassium since last week, even stopping the GHK-cu this weekend and I still feel crappy.
I started my new kit a month ago and the first two weeks I felt almost nothing, so that is why I titrated up in the first place.
I feel slightly better today but I think once I stop feeling this way I am going to try to split up my dose and take 2.5mg every 3.5 days and see if that helps.

This actually sounds VERY similar to what I’m experiencing, especially the delayed “what the hell is happening to my body” aspect of it.
The malaise/apathy part is something I really relate to too. It’s not just nausea, it’s this strange full-body “I can barely function as a human being” feeling.

I also thought dehydration/electrolytes might be the main issue at first and started aggressively hydrating, but it never fully explained the severity of the symptoms.

What you said about increasing because the previous weeks felt “too mild” is really interesting too. It honestly makes me wonder whether there really can be some kind of delayed accumulation/saturation effect with these peptides.

Maybe when I restart, I could even consider splitting my microdose at first.

Also: I kinda love you for sharing such a similar experience and I seriously admire you for surviving this without even skipping a dose, because right now I am far too traumatized to even LOOK at a syringe.

 

[WLBLD]

Honestly, the build-up/accumulation theory genuinely makes the most sense to me right now, especially combined with stress and being sick at the same time.

And no, it wasn’t a new vendor or a new batch. Same source I had already been using and tolerating before this happened.

What really threw me off is that the reaction felt so sudden and disproportionate compared to my “usual” Tirz side effects.

Maybe its also bc the antiviral combo. I hope you feel better soon!!

 

[MsGizmo]

To make things even weirder, I simultaneously caught a monster cold and ended up taking antivirals for suspected shingles/herpes zoster because I had this horrible “needles in the skin” sensation.
Except… no rash. No blisters. Nothing. So apparently even my possible shingles wanted to stay mysterious and dramatic.

Why are we to assume that the issue is actually the tirz and not the virus?

 

[Mara_aa]

The needles/sunburn "allodynia" definitely does not need to be bilateral for it to be from the Tirz (or from Reta). I've experienced it on both peptides, and presents wherever it wants- I've had it: around ankles, tops of the feet, upper thighs, glutes, back, stomach, even my cheek/face (only the right side). I would pin it (pun intended) on the Tirz before shingles.

… out of my own lack of knowledge, I had only ever heard about the “needles/allodynia/sunburn skin” thing with Reta, not Tirz, so when it appeared only on one side I completely trusted the suspected shingles/herpes zoster diagnosis.

“I would pin it on the Tirz” deserves an award lol

Seriously, thank you so much 🫶 I’m absolutely telling my doctor about this tomorrow morning… although I probably won’t be thanking him for the 7 days of antivirals that may have flattened me even more.

 

[Mara_aa]

Why are we to assume that the issue is actually the tirz and not the virus?

The reason I keep suspecting Tirz is because the symptoms accompanying the extreme fatigue are very specifically: severe nausea, acid reflux, extreme gastric slowing/fullness, inability to eat or drink normally, etc.

Those are basically the exact same symptoms I experienced when I first started Tirz, just amplified to an extreme level this time

 

[Mara_aa]

Maybe its also bc the antiviral combo. I hope you feel better soon!!

Yes, I do suspect the antivirals may have made everything worse on top of what was already happening lol
Thank you so much 🫶 I really hope this nightmare starts fading soon too

 

[Mara_aa]

I have, and to be honest I have no good reason for not trying it other than I had already purchased a few kits of Tirz. I will probably take another look once I run out or cant hit my goal weight.

Honestly, that is an extremely valid reason lol

And if Tirz is still working for you overall, it totally makes sense not to switch prematurely. That was exactly my plan too before my body decided to stage this dramatic protest.

 

[desinr-gal]

The Tirz reaction/symptoms definitely started first. The antivirals were started a few days later because of the suspected shingles/herpes zoster situation.

And yes, antivirals can also be rough, which honestly makes the whole thing even more confusing to untangle 😭

Sounds awful! I am sorry you are having this experience

 

[BNLFL]

… out of my own lack of knowledge, I had only ever heard about the “needles/allodynia/sunburn skin” thing with Reta, not Tirz, so when it appeared only on one side I completely trusted the suspected shingles/herpes zoster diagnosis.

“I would pin it on the Tirz” deserves an award lol

Seriously, thank you so much 🫶 I’m absolutely telling my doctor about this tomorrow morning… although I probably won’t be thanking him for the 7 days of antivirals that may have flattened me even more.

The reason I keep suspecting Tirz is because the symptoms accompanying the extreme fatigue are very specifically: severe nausea, acid reflux, extreme gastric slowing/fullness, inability to eat or drink normally, etc.

Those are basically the exact same symptoms I experienced when I first started Tirz, just amplified to an extreme level this time

Yes, I do suspect the antivirals may have made everything worse on top of what was already happening lol
Thank you so much 🫶 I really hope this nightmare starts fading soon too

Honestly, that is an extremely valid reason lol

And if Tirz is still working for you overall, it totally makes sense not to switch prematurely. That was exactly my plan too before my body decided to stage this dramatic protest.

Not sure you know, but you can multi quote and reply to each separately.

 

[Mara_aa]

Sounds awful! I am sorry you are having this experience

Thank you so much 🫶
I’m very slowly improving, so I’m trying to stay hopeful!

 

[Mara_aa]

Not sure you know, but you can multi quote and reply to each separately.

I have to confess that I do know about that feature because I’ve seen other users use it, but on my phone I keep trying and somehow end up making a mess and then can’t find all the quotes I wanted to reply to anymore.
I don’t really have the same problem on PC, but outside of work hours I barely use it.
I hope I’m not becoming annoying by replying to individual posts one by one.
Still, thank you for the lesson.

 

[BNLFL]

I have to confess that I do know about that feature because I’ve seen other users use it, but on my phone I keep trying and somehow end up making a mess and then can’t find all the quotes I wanted to reply to anymore.
I don’t really have the same problem on PC, but outside of work hours I barely use it.
I hope I’m not becoming annoying by replying to individual posts one by one.
Still, thank you for the lesson.

Nah, just wasn't sure you knew.

 

[Mara_aa]

Nah, just wasn't sure you knew.

Got it! As long as I'm not being annoying, that's what matters ahah
Thanks for patience and for taking the time to explain anyway. I really appreciate it.

 

[lessthanhalf]

I also get skin sensitivity / abnormal sensations from tirz. I got it when increasing doses originally, and now I am on both tirz and reta, it gets obviously worse with tiny dose increases of either reta or tirz.

It is also weirdly patchy, often worse on my left shoulder, or both arms and occasionally it hits local leg nerves, thankfully it is pretty mild unless I accidentally have a slightly higher dose.

I have tried to research this and really cannot find much on it other than being mentioned as a side effect in some of the studies. It is interesting that it seems to be more likely from reta, and it was rare in the semaglutide studies, but in the high dose semaglutide studies of 7.2 and 16 mg, it was very common , up to 20%. So given that sema does not affect anything other than GLP-1, it more or less has to be a GLP-1 effect, which totally fails to explain why it seems to be more common with reta. I have discussed this with chatgpt , it does not seem to think there are any concerns about actual long term nerve damage occurring from it, and as far as I know there are no reports of nerve damage from GLP drugs, which is reassuring I guess.

There is no obvious pharmacology explanation for why you suddenly got much more severe side effects. Apart from some of them being made worse by having a virus at the same time. All you can really do is avoid dosing until the effects have settled down a lot, and restart a fair bit lower, and half the dose twice as often will make it easier to adjust doses up and down if needed.

 

[sheilarae74]

The malaise/apathy part is something I really relate to too. It’s not just nausea, it’s this strange full-body “I can barely function as a human being” feeling.

THIS IS EXACTLY HOW I FELT! I had to force myself to do everything for the last 10 days.

What you said about increasing because the previous weeks felt “too mild” is really interesting too. It honestly makes me wonder whether there really can be some kind of delayed accumulation/saturation effect with these peptides.

Maybe when I restart, I could even consider splitting my microdose at first.

Also: I kinda love you for sharing such a similar experience and I seriously admire you for surviving this without even skipping a dose, because right now I am far too traumatized to even LOOK at a syringe.

You might be right about the accumulation thing. The last dose of 5mg I took last sunday was from a new vial, as the last vial didn't even even last 4 weeks. I am thinking this new vial might be more than the 20mg it was supposed to be. Plus this time I reserved some of the BAC to prime the filter and flush the last bit of reta out of it after I filtered it. The COA some guy showed me of the vial he had tested from that same batch had 22mg in it. That's the only thing I can think of. I was supposed to take my dose last night but I figured I better wait until I'm well.
Since I feel a lot better today, I think I am going to pin 2mg tonight and then another 2mg on Friday morning if things go well.

I don't blame you for being apprehensive about starting back up. I never want to feel like that again and I'm sure you don't either. I guess that's risk we take doing these China peps. I'm 12lbs from my goal and I'm not in a big hurry so I am gonna split for a while and see how it goes.

 

[Mara_aa]

I also get skin sensitivity / abnormal sensations from tirz. I got it when increasing doses originally, and now I am on both tirz and reta, it gets obviously worse with tiny dose increases of either reta or tirz.

It is also weirdly patchy, often worse on my left shoulder, or both arms and occasionally it hits local leg nerves, thankfully it is pretty mild unless I accidentally have a slightly higher dose.

I have tried to research this and really cannot find much on it other than being mentioned as a side effect in some of the studies. It is interesting that it seems to be more likely from reta, and it was rare in the semaglutide studies, but in the high dose semaglutide studies of 7.2 and 16 mg, it was very common , up to 20%. So given that sema does not affect anything other than GLP-1, it more or less has to be a GLP-1 effect, which totally fails to explain why it seems to be more common with reta. I have discussed this with chatgpt , it does not seem to think there are any concerns about actual long term nerve damage occurring from it, and as far as I know there are no reports of nerve damage from GLP drugs, which is reassuring I guess.

There is no obvious pharmacology explanation for why you suddenly got much more severe side effects. Apart from some of them being made worse by having a virus at the same time. All you can really do is avoid dosing until the effects have settled down a lot, and restart a fair bit lower, and half the dose twice as often will make it easier to adjust doses up and down if needed.

Thank you so much for taking the time to write such a detailed reply. This is genuinely very helpful and reassuring to read.

What you describe about the skin sensitivity being patchy/random and clearly worsening with dose increases sounds incredibly similar to what several people in this thread are describing, and honestly I had no idea this side effect could be this “real” and still so poorly understood.

The fact that you looked into the studies and found that it appears even with high-dose semaglutide is also really interesting. Obviously none of us can fully explain the mechanism, but it does make me feel a bit less like I’m losing my mind 😅

And thank you especially for mentioning the lack of evidence regarding long-term nerve damage. I know ChatGPT is not a medical authority, but hearing that there do not seem to be reports of permanent nerve injury from GLP drugs is still psychologically reassuring when your skin suddenly feels bizarre.

Your explanation about the virus potentially amplifying already-existing GLP side effects honestly makes a lot of sense too. Maybe my body just hit some kind of temporary “too much at once” threshold.

For now I am definitely not dosing again until things calm down substantially. And if I ever restart, I think smaller and more frequent split doses will probably be the safest approach for me too.
Seriously, thank you again for such a thoughtful and balanced response