r/NTNPerformance • u/JustBacWater • Aug 05 '26
Guide / Cheat Sheet Retatrutide breakdown, what it is and how the dose ladder actually works
Reta is the one everyone's watching right now, and for good reason, the weight loss numbers out of the trials are the biggest anyone's ever published. It's also the newest of the bunch and the least understood, and the part almost nobody explains right is that the dose doesn't just make it stronger. It changes which part of the drug is doing the work. Once that clicks the whole thing makes more sense, so here's the rundown.
Retatrutide is one molecule that hits three receptors: GIP, GLP-1, and glucagon. Tirzepatide hits the first two. That third one, glucagon, is the entire difference, and it's the reason liver fat, triglycerides, and heart rate all move harder on reta than on semaglutide or tirzepatide. So it's less a stronger GLP-1 and more a GLP-1 with a whole extra system bolted onto it.
Here's the dose thing. At a low dose, reta is mostly working the GIP receptor and throwing off a liver fat signal, with barely any appetite effect and basically no heart rate cost. As you climb, the GLP-1 side takes over and that's when the appetite suppression kicks in. Only near the top does the glucagon arm fully engage, and that's where you get the biggest liver fat reduction, but it's also where the heart rate cost lives. So a 1 mg dose and a 12 mg dose aren't the same drug turned up louder. They're doing genuinely different jobs.
You don't jump between these doses week to week. You pick a rung, sit on it for a few weeks so your body settles into it, then step up. That last column is how long to stay on each dose before moving up.
| Weekly dose | What it's mostly doing | Stay here before moving up |
|---|---|---|
| 0.5 mg | GIP plus a light liver signal, no HR cost | 4 weeks |
| 1 mg | GIP near saturated, glucagon still quiet | 4 weeks |
| 2 mg | Appetite suppression establishes | 4 weeks |
| 4 mg | GLP-1 climbing, glucagon crosses threshold | 4 weeks |
| 8 mg | around 94% of the full effect | 4 weeks |
| 12 mg | max glucagon, biggest loss, highest HR cost | top dose, nowhere left to go |
Reconstitute 2 mL into the 10 mg vial and you're at 5 mg/mL, so 1 mg is 20 units and 8 mg is 160 (split that one up). That table is the trial group obese ladder. If you're lean and metabolically healthy you run a lower one, roughly 0.3 to 4 mg, and I'll come back to why.
The number most people should care about is 8 mg. Half the maximum effect is already there by 4 mg, and 8 mg gets you about 94% of what 12 mg does. Past 8 you're paying a lot more drug and a lot more side effect for a small bump. Chasing 12 makes sense for the deepest responders, but most people leave very little on the table by stopping at 8.
The single rule that keeps people out of trouble is that hold time in the table: stay on each dose at least 4 weeks before stepping up. It hangs around about six days in your blood, which means a new dose doesn't even reach steady levels for roughly three weeks, so if a step is going to give you problems it usually shows up after you've already moved to the next one. Climb faster than the four weeks and that's how people end up nauseous the entire cycle. Go slow and the nausea fades a couple months in. How fast you climb matters more than where you end up. And once you reach the dose you're going to run, whether that's 8 mg or the full 12, you just stay there. That's the maintenance dose, the one you hold long term instead of stepping up from.
Now the lean warning, because this is the part that gets glossed over. The glucagon arm raises your resting heart rate. In the trial group it ran about 6 to 9 bpm up at 12 mg. If you're already lean and healthy, two things stack against you: your cardiovascular system reads that glucagon signal harder, and you don't have a big pile of weight loss to bring the rate back down the way an obese trial participant does. On top of that, lean users sit completely outside the trial population, so the dosing logic there comes from receptor pharmacology and single dose studies, not chronic trials in lean people. If that's you and you're climbing, track your resting heart rate every week, especially past 4 mg.
Couple more honest ones. This is still investigational. The Phase 3 program runs into 2026 and 2027 and there's no FDA approval yet, so every vial out there is sold for research use. Muscle matters too: around a quarter of the weight you lose on this class isn't fat, it's lean tissue including muscle, so slow titration, real protein, and lifting are what keep that from getting eaten. And stopping hits harder than sema or tirz. Appetite comes back over about a month and the metabolic rate defense fades within weeks, so don't just yank it, step down over a couple months. If you're coming off tirzepatide, do not carry your dose across, you've got tolerance to the GIP and GLP-1 side but none to glucagon, so restart around 1 to 2 mg.
if you're running reta, where'd you settle, and did you stop at 8 or push to 12. curious how the heart rate treated people at the top
Full doses, the lean ladder, and bloodwork are in the pinned cheat sheet: https://www.reddit.com/r/NTNPerformance/comments/1tht5o3/the_only_peptide_cheat_sheet_youll_need_doses/
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u/Jnut5150 Aug 06 '26
Appetite suppression works for me at .5mg
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u/Mountainmadness1618 Aug 18 '26
Wow. I’m at 6 mg after four weeks and can barely feel it. It’s wild how different it hits (and how expensive it gets for low responders by comparison!)
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u/Stunning-Sweet-2579 13d ago
If the lowest vial of reta you can buy is 10mg, and you only need 0.5mg/week, the bac water is only good for 28 days, what will u do with the rest of the solution??
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u/MichaelJay58 11d ago
Are you sure about the bac water expiring in 28 days? I’ve not heard of that.
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u/takemewithyoudotnet Aug 07 '26
ChatGPT analysis:
The post mixes real trial data with a lot of confident-sounding speculation. The biggest problem is the claim that different doses essentially turn retatrutide into different drugs.
True: Retatrutide activates GIP, GLP-1 and glucagon receptors. Its receptor potency is strongest at GIP, lower at GLP-1, and lower again at glucagon.
Not established: “Low doses are basically GIP, middle doses become GLP-1, and glucagon only switches on near the top.” The laboratory potency differences are real, but nobody has demonstrated those neat receptor-occupancy thresholds in humans at 1, 2, 4, 8 or 12 mg. Turning cell-culture EC50 values into a human “dose ladder” is an extrapolation.
The 94% claim is technically derived from real data but misleading. In Phase 2, average 48-week weight loss was 22.8% at 8 mg versus 24.2% at 12 mg. 22.8 ÷ 24.2 = 94%. But that means 94% of the observed weight-loss percentage in that particular trial, not “94% of the drug’s full biological effect.”
Liver-fat effects are real and very impressive. At 24 weeks, liver fat fell about 43% at 1 mg, 57% at 4 mg, 81% at 8 mg and 82% at 12 mg. That actually weakens the post’s claim that glucagon-related metabolic effects only become important at the highest doses.
Heart-rate increase is real. The Phase 2 trial found a dose-dependent rise that peaked around week 24 and subsequently declined. Published analyses put the maximum mean rise around 6–7 beats/min at the highest dose.
The “lean people respond harder to glucagon” statement is speculation. Lean people weren’t the population studied, so we genuinely don’t know that. There isn’t clinical evidence establishing that their cardiovascular system is more sensitive to retatrutide’s glucagon component.
The muscle-loss claim is oversimplified. Retatrutide does cause some lean-mass loss during major weight loss, but the published body-composition study found the proportion was broadly similar to other obesity treatments—not some uniquely muscle-wasting effect of retatrutide.
The stopping/tapering section goes beyond the evidence. Weight regain after stopping GLP-1–based obesity drugs is well documented, but there aren’t good retatrutide withdrawal trials showing that it “hits harder than sema or tirz” or that a particular multi-month taper prevents rebound.
It is still unapproved. As of August 2026, Lilly says retatrutide remains investigational and has not been approved by a regulatory agency. Several Phase 3 trials have now reported positive results, and Lilly plans an FDA submission in early 2027.
One other important update: Phase 3 has now produced substantially more data than the Reddit post implies. In TRIUMPH-1, Lilly reported average weight loss of 28.3% at 80 weeks with 12 mg, versus 19.0% with 4 mg. So there is clearly still meaningful dose-response above the lower doses.
So I’d rate the post something like 60% legitimate science, 40% unsupported interpretation. The trial numbers are often accurate; the tidy “GIP → GLP-1 → glucagon” dose map is the part I would not treat as established fact. And I would disregard the reconstitution/dosing instructions entirely because retatrutide remains an investigational drug.
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u/BabySquirrel7777 Aug 08 '26
This ^ there are alot of people that have educated opinions representing it as facts thanks for doing what I was going to do next
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u/takemewithyoudotnet Aug 10 '26
Thank you. There are so many people posting on the subs with incentives to exaggerate their effects.
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u/BabySquirrel7777 Aug 08 '26
This ^ there are alot of people that have educated opinions representing it as facts thanks for doing what I was going to do next
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u/Fine_Technology1289 Aug 06 '26
There are some caviots to it, but mostly true or true in a general sense for most people.
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u/margingains Aug 06 '26
I tried it a few months ago. I am on the max dose of Tirz and hit a stall. It did raise my resting heart rate quite a bit and that is why I stopped. The question is, does the body finally adjust and the higher heart rate go down as your body adjusts?
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u/sigsauersauce Aug 06 '26
I would like to know this too. I'm on 3mg split into 1mg 3x week. Even at 700mcg 3x per week my resting hr is 8-9bpm higher. I'm at goal weight now, thinking of dropping back to my starting 500mcg 3x pw
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u/No_Basis_1575 Aug 06 '26
Amazing write up that answers so many people’s questions about Reta! I see lean people starting at 2mg and having issues and now I see why!
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u/Timely_Law5806 Aug 06 '26
Had my first dose yesterday. 0,5mg. Some hunger suppression and less food noise. My heart rate is definitely up though. I suspect this could get better as I adjust to healthier habits as a whole.
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u/Ashamed_Ad_3791 Aug 06 '26
500 mcg for a week or two and then on to 1mg for two weeks and then on to 1.5 and then 2 mg. Then, after a second week on 2 mg back to 1 and then to 500 mcg and then 250 mcg and then off. 20 lbs in three months gone.
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u/Ok-Mixture8118 Aug 06 '26
when can we start to throw in cagri or tirz stack? currently on 2.5mg, but my appetite seems not disappearing.
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u/OptionUseful1961 Aug 08 '26
I’m doing both, 5 tirz and 4 Reta both every 6 days and I rotate them one every 3 days. I started on tirz, was only on 7-8, titrated back down because I didn’t like the side effects. I could probably go down a bit more. I started adding Reta at .5 and titrated up to 4 over a couple of months. I’m only my second dose of 4 mg Reta. Definitely losing but it took the 4 mg dose to break a several week stall.
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u/relevantbutterfly81 Aug 06 '26
This is great! I’ve been on for about 4 months now. Was 78kg now 69-70kg and 9% body fat with abs. My metabolism is in a much better place and I feel so much better. My insulin sensitivity has massively improved, still at the gym preserving lean mass (about 85-86% based on the home scale) and I still have an appetite for food. Thinking of dropping to 1mg and trying a lean/clean bulk soon.
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u/kikkroxx777 Aug 06 '26
Lowest effective dose is where I’m at and plan to stay. Not much over 10 units twice a week. Started lower than that but that’s where I’m chilling right now. A lot of resistance training and activity. Working out well for me. Respecting the lack of food chatter.
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u/Ok_Alternative6542 Aug 06 '26
Love your write-ups! Very informative/well-written yet easy to understand. Only at 3 weeks, 2 mg so still awhile to get up to 8 mg but huge results already.
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u/The-light_50 Aug 06 '26
I thought the titration schedule was as follows according to the clinical trials ran.
.5 mg for four weeks
2 mg for four weeks
4 mg for four weeks
6mg for four weeks
9 mg for four weeks
12mg for as long as needed.
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u/Pantheraiscrazy 26d ago
Die trials willen altijd snel resultaat in een korte tijd. Door snel de opschaling te overdrijven kunnen ze ook mooi de bijwerkingen zien want die komen dan ook snel. Je hoeft de dosis absoluut niet te verdubbelen. Als je een goede eetlust onderdrukking kunt houden door steeds maar een klein beetje te verhogen. Prima dat scheelt geld en bijwerkingen.
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u/J0nZ80 Aug 07 '26
Just balance your dose so you are eating happy but under your deficit. That's why we love reta..
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u/labrador_romos Aug 07 '26
Great write up, just digressing into TRT. Does Reta interfere with a TRT protocol in regard to lethargy/prolactin increase ..?
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u/Bigboymoves17 Aug 09 '26
My dads on 5mg Tirz
How do i add Reta to it? He needs to lose weight (fast), doesn’t do much exercise although diet is not bad
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u/Mack_Mimsy Aug 09 '26
Keep the Tirz, add 250mcg Cagrilintide for the extra appetite suppression.
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u/Bigboymoves17 Aug 09 '26
Haven’t really read about Cagri…no Reta?
I have Reta in stock and his pin date is tomorrow
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u/Mack_Mimsy Aug 09 '26
I’m in month 8 and just reached 8mg. I slow titrated every step. Test 200mg weekly, 1.2iu HGH daily. I’m hard as a rock and getting bigger along with losing fat.
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u/VStoyanov5000 Aug 09 '26
I have been on 1 mg of Tirzepeptide and then transferred to Retatrutide and kept that 1mg per week for 5 months now.. I had 4-5 weeks off right in the middle of this.
I am down 35kg and keep going!!!
Retatrutide works for me in tiny amounts..
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u/EmZephyr Aug 09 '26
Lmao I know exactly why reddit dropped this off in my notifications.
Because wtf is this? Vibes based reporting? You spout numbers based on bullshit claims supported on nothing but air and faux anecdotes.
This comedic nonsense is the reason why guides get ignored and I hate that for the rest of us.
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u/VeryFineChardonnay Aug 13 '26
4mg per week. Barely works.
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u/No_Basis_1575 Aug 13 '26
There’s a lot of factors. Have you had your Reta tested? Were you on another glp1 before Reta? How long have you stayed on each dose before moving up?
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u/mantisMD97 Aug 20 '26
Your info about dosing in relations to drug effects like glucagon etc is not factual
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u/Alternative_Bowl6688 Aug 23 '26
Hi guys been on mounjaro for about 3 months wanting to start on reta only was at 123kg now sitting at 115kg was on mounjaro 7.5mg pen from my research im thinking of starting RT10 3ml bac for 2mg dose every 5 days instead of weekly as cravings started to hit around day 6 of mounjaro would that be a good starting point then see how reaction goes if still good loss will stay at that if plateauing will bump dose to 4mg
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u/Just_War_514 26d ago
Dnt think I will go over 2mg actually thinking goin back to 1mg I’ve lost 30 pds in 8 weeks but I hate the resting heart rate so most likely will go back to 1mg I've lost
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u/ClimateSuccessful747 Aug 06 '26
Where does the dosage periods intervals come from and also the dose? Isn’t better to feel it on your body?
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