Do Reta and Tirz treat people the same way?

[spanky2026]

A question has been nagging me about a pattern I keep encountering. I take it to be anecdotal, and I honestly can't tell how often it actually holds for real users:

A common report goes something like this: someone had zero side effects on (insert Tirz or Reta), and after adding or switching to (the other) they still had zero. Sure, everyone is different and all that — but I'd like to know whether a clean run on one is at least a semi-reliable signal for how the other will treat you?

 

[woundcarping]

Tirz and Reta give me next to nothing in the way of sides.... Sema, though, is its own animal.

My guess is you'd be fine on Reta, and moving over to Tirz ought to go smoothly. Going the opposite direction can get rough, though — it really depends on your response and how you manage the bridge.

 

[spanky2026]

woundcarping said:

Tirz and Reta give me next to nothing in the way of sides.... Sema, though, is its own animal.

My guess is you'd be fine on Reta, and moving over to Tirz ought to go smoothly. Going the opposite direction can get rough, though — it really depends on your response and how you manage the bridge.

Sema's side effect profile is clearly the harsher one, which is exactly why plenty of people rule it out from the start.

 

[woundcarping]

spanky2026 said:

woundcarping said:

Tirz and Reta give me next to nothing in the way of sides.... Sema, though, is its own animal.

My guess is you'd be fine on Reta, and moving over to Tirz ought to go smoothly. Going the opposite direction can get rough, though — it really depends on your response and how you manage the bridge.

Sema's side effect profile is clearly the harsher one, which is exactly why plenty of people rule it out from the start.

At 18-20mg of Reta, I never figured .25mg of Sema would land that hard. I still "like it", but with "plenty of everything" on hand I may move to Tirz or an Amylin agonist once I fine-tune my Reta dose somewhere between goal weight one and two. Curious whether sleep quantity comes easier and my RHR settles down a bit.

Starting out 282lb, GW1 200lb, GW2 ~180lb, sitting at 200lb these days, 34 weeks in. I still mean to shed these last 20lb with purpose, though I'd like to see whether I can take my foot off the gas and just cruise, roughly holding my 1% w/w rate of loss.

 

[Speedy]

My only experience is with the brand name, plus Tirz and Reta. Reta and Tirz hit me differently. The Tirz sides are obviously the same ones the brand name M brings.

Reta I simply couldn't tolerate. My blood pressure already runs low, and Reta pushed it down even lower until I felt awful.

Anyway. I'm hunting for that supposedly hilarious ghk-cu thread — somebody send a link my way if you have it.

And since I mostly lurk, I keep checking whether a few years here has moved me past newbie status.

—nope, still a newbie

 

[Oldguy]

Go on, pop open that Reta you've been stashing in the freezer.

 

[spanky2026]

Oldguy said:

Go on, pop open that Reta you've been stashing in the freezer.

Yeah, I'll get to it eventually — no rush. Meanwhile I keep reading, and what I find is completely inconsistent: some folks transition without a hitch, others get flattened by the switch. So I really do want to hear from people here, yet almost nobody has spoken up. Back to reading.

 

[Oldguy]

The crowd around here has changed a lot from what it was 6 months back

 

[lessthanhalf]

Going by my own experience, and by plenty of reading on how these drugs act at the different receptors, reta and tirz come out remarkably alike on side effects. The main split is that reta ramps up sympathetic nervous system activity further, which raises heart rate and can bring insomnia or other effects along with it. On GIP agonism reta is the weaker of the two, so its gastrointestinal side effects run worse than tirz's, since GIP works against the unpleasant effects of GLP-1 agonism — though the gap isn't enormous. Reta also appears to trigger more dysasthesia / skin sensory effects than either sema or tirz, and I've yet to see a decent explanation for why it shows up more with reta than the rest.

Where sema sits is clearly worse for gastrointestinal side effects than reta or tirz, which follows from having no GIP agonism at all. Food aversion and malaise are likelier with it too, and while less frequent, it can also produce skin sensory problems — oddly, only at very high doses.

For a whole year I dealt with terrible nausea, malaise and food aversion on fairly low doses ( 0.8mg/w ) of sema that a doctor prescribed, until I found grey peptides — yet 15mg of tirz gave me next to nothing, and adding 5mg of reta barely registered. That contrast was far, far larger than I had anticipated.

Broadly speaking, these compounds engage the receptors in comparable fashions. The GI trouble traces to glp-1; gip looks to be largely protective against glp-1 side effects; and the rise in heart rate comes from glucagon agonism. So you can get a decent read on how tirz will treat you by trying reta, and the reverse, though individual reactions to glp drugs are idiosyncratic — nothing is guaranteed.

Taken together, tirz is the gentlest of the three, reta isn't far behind it, and sema trails both by a fair margin.

 

[Builderman]

About a year back I ran 2.5MG of trizepatide for a month. At that point I hadn't done any real research, and honestly my eating was still terrible, I wasn't drinking enough water, and I had no real idea what I was doing. The heartburn it gave me was the worst I've ever experienced — nothing would shift it, and it hung around for another couple of weeks after I quit the tirz. I'm almost sure that came from the poor diet and being under-hydrated while on it.

Jump to this year and I began Reta. Nothing bad happened until I got impatient and pushed the titration far too quickly up to 7mg, which left me with fairly unpleasant dysesthsia for a few weeks. I'm still sitting at 7mg, and 3 weeks ago I stacked 2.5 mg of tirz on for extra appetite suppression, which has worked great.

Other than the dysesthesia, which has cleared up, this round on Reta and tirz has brought no real negative effects. I've even dropped 45 pounds, which thrills me.

 

[Flash-BCR]

Tirz had me at 5mg twice weekly, Friday and Monday...I then pinned 2mg of reta (1mg Friday night, then 1mg Saturday morning once I woke up not dead ) and since the reta wasn't producing much in the way of symptoms I decided to get cute and pinned 6mg of tirz on the Monday....hell, from how the GI symptoms arrived you'd have thought I pinned 10mg...All my worrying had been about the reta, and it was the tirz that bit me....Still, I'll edge the reta up to 4mg as soon as I can, while always keeping in mind that reta bites harder than tirz...

 

[unclebuff702]

woundcarping said:

Tirz and Reta give me next to nothing in the way of sides.... Sema, though, is its own animal.

My guess is you'd be fine on Reta, and moving over to Tirz ought to go smoothly. Going the opposite direction can get rough, though — it really depends on your response and how you manage the bridge.

That matches my experience.

Sema honestly had me convinced I was dying. As it turns out, the doctor who wrote the RX (a real MD, not some health spa lol) put me on 2.4mg from the start. Two years on, while researching alternatives, I learned that either a) that doctor wanted me dead, b) he was wildly ignorant or negligent, or 3) he figured I was fat enough to justify jumping straight to the end zone lol.

So yes, maybe I'm biased when I say sema hit different — but Tirz and Reta have given me almost nothing in the way of sides, and I'd sooner stick a fork into a live socket than revisit how my very first Sema dose felt.

 

[AngieHolmes]

Speedy said:

My only experience is with the brand name, plus Tirz and Reta. Reta and Tirz hit me differently. The Tirz sides are obviously the same ones the brand name M brings.

Reta I simply couldn't tolerate. My blood pressure already runs low, and Reta pushed it down even lower until I felt awful.

Anyway. I'm hunting for that supposedly hilarious ghk-cu thread — somebody send a link my way if you have it.

And since I mostly lurk, I keep checking whether a few years here has moved me past newbie status.

—nope, still a newbie

Reta doesn't have a "brand name" on the market yet . . .

 

[woundcarping]

unclebuff702 said:

woundcarping said:

Tirz and Reta give me next to nothing in the way of sides.... Sema, though, is its own animal.

My guess is you'd be fine on Reta, and moving over to Tirz ought to go smoothly. Going the opposite direction can get rough, though — it really depends on your response and how you manage the bridge.

That matches my experience.

Sema honestly had me convinced I was dying. As it turns out, the doctor who wrote the RX (a real MD, not some health spa lol) put me on 2.4mg from the start. Two years on, while researching alternatives, I learned that either a) that doctor wanted me dead, b) he was wildly ignorant or negligent, or 3) he figured I was fat enough to justify jumping straight to the end zone lol.

So yes, maybe I'm biased when I say sema hit different — but Tirz and Reta have given me almost nothing in the way of sides, and I'd sooner stick a fork into a live socket than revisit how my very first Sema dose felt.

Wow — our experiences sound like they were wildly different!

Starting Sema, the "worst sides" landed on me, while Reta or Tirz barely registered. Malaise, an unsettled stomach, appetite suppressed too far. Splitting my first .25mg dose into .125mg doses afterward is what largely resolved it.

Beginning at 2,4mg had to have been a wild ride. What did that do to your weight while it was going on?

 

[spanky2026]

unclebuff702 said:

woundcarping said:

Tirz and Reta give me next to nothing in the way of sides.... Sema, though, is its own animal.

My guess is you'd be fine on Reta, and moving over to Tirz ought to go smoothly. Going the opposite direction can get rough, though — it really depends on your response and how you manage the bridge.

That matches my experience.

Sema honestly had me convinced I was dying. As it turns out, the doctor who wrote the RX (a real MD, not some health spa lol) put me on 2.4mg from the start. Two years on, while researching alternatives, I learned that either a) that doctor wanted me dead, b) he was wildly ignorant or negligent, or 3) he figured I was fat enough to justify jumping straight to the end zone lol.

So yes, maybe I'm biased when I say sema hit different — but Tirz and Reta have given me almost nothing in the way of sides, and I'd sooner stick a fork into a live socket than revisit how my very first Sema dose felt.

Say you found a different doctor after that?

 

[reta-stacker]

Oldguy said:

The crowd around here has changed a lot from what it was 6 months back

Was it a positive thing, or was it negative?

 

[chewonmysac]

reta-stacker said:

Oldguy said:

The crowd around here has changed a lot from what it was 6 months back

Was it a positive thing, or was it negative?

Rough in the short run, but a good thing over time. Once compounding GLP looked like it might vanish for good, people from Reddit poured into the site hunting for alternatives — human nature, mine included, in the fall of 2025. Newcomers were making fresh threads within the 1st week of joining, repeating the exact ridiculous questions they'd been asking on Reddit. In time I expect they'll either settle into this kind of forum or drift back to Reddit, merging once more into the broader population, ranking alongside incarceration. I can always spot a new poster who's about to nuke themselves. Sometimes the wiser play is to stay quiet, keep watching where things go, collect whatever data comes your way, and aggregate it.

 

[woundcarping]

chewonmysac said:

reta-stacker said:

Oldguy said:

The crowd around here has changed a lot from what it was 6 months back

Was it a positive thing, or was it negative?

Rough in the short run, but a good thing over time. Once compounding GLP looked like it might vanish for good, people from Reddit poured into the site hunting for alternatives — human nature, mine included, in the fall of 2025. Newcomers were making fresh threads within the 1st week of joining, repeating the exact ridiculous questions they'd been asking on Reddit. In time I expect they'll either settle into this kind of forum or drift back to Reddit, merging once more into the broader population, ranking alongside incarceration. I can always spot a new poster who's about to nuke themselves. Sometimes the wiser play is to stay quiet, keep watching where things go, collect whatever data comes your way, and aggregate it.

Reading that stirred something deep in me.

 

[deleted.user.25]

spanky2026 said:

A question has been nagging me about a pattern I keep encountering. I take it to be anecdotal, and I honestly can't tell how often it actually holds for real users:

A common report goes something like this: someone had zero side effects on (insert Tirz or Reta), and after adding or switching to (the other) they still had zero. Sure, everyone is different and all that — but I'd like to know whether a clean run on one is at least a semi-reliable signal for how the other will treat you?

What I noticed is that Tirz gave me Zero side effect, while Reta, which went into the mix on Friday, left me a bit drained yesterday — and today I feel Great. Much too soon to call it, though my body tends to be predictable. The fact that today wasn't harder on me suggests the worst has passed. These last 27lbs I'll run the mix, chasing my 145lbs goal, alternating two days on and two days off of each.

 

[deleted.user.25]

Builderman said:

About a year back I ran 2.5MG of trizepatide for a month. At that point I hadn't done any real research, and honestly my eating was still terrible, I wasn't drinking enough water, and I had no real idea what I was doing. The heartburn it gave me was the worst I've ever experienced — nothing would shift it, and it hung around for another couple of weeks after I quit the tirz. I'm almost sure that came from the poor diet and being under-hydrated while on it.

Jump to this year and I began Reta. Nothing bad happened until I got impatient and pushed the titration far too quickly up to 7mg, which left me with fairly unpleasant dysesthsia for a few weeks. I'm still sitting at 7mg, and 3 weeks ago I stacked 2.5 mg of tirz on for extra appetite suppression, which has worked great.

Other than the dysesthesia, which has cleared up, this round on Reta and tirz has brought no real negative effects. I've even dropped 45 pounds, which thrills me.

Great news — that counts as a Win. Happy for you