CommunityStacking & Switching

Those who stack Reta and Tirz—do you pin same time or alternate?

57 replies36 peopleApr 17, 2026☆ Follow
Summary

When stacking tirzepatide and retatrutide, should doses be taken on the same day or staggered on different days?

Users report a range of personal schedules with no single consensus. Many stagger injections by 2–4 days to monitor individual side effects, smooth appetite control, and avoid overlapping peaks. Others take both on the same day without issues and find it simpler. Half-lives near 5–6 days influence spacing decisions, and outcomes depend on each person's response.

What this discussion establishesWhere people disagree

Whether same-day dosing increases side effects or is perfectly tolerable; some report problems while others experience none.

Still open

No agreement on an optimal universal schedule or exact dose combinations that work for everyone.

Nothing here is advice.

57 replies · 36 people · page 1 of 2
PatientHarbour23archiveopening postApr 17

I finally mixed up my Reta today and plan to begin this weekend. My next Tirz shot is tomorrow since I split the dose, and I'm wondering whether to do the usual Tirz along with the small starting Reta amount of 0.5 at once or save Reta for tomorrow and shift Tirz to Sunday or Monday.

SharpCinder28archiveApr 17

I keep them on separate days. I took 4 mg tirz today so the soonest I would add reta is two days later.

KeenSignal54archiveApr 17

I just avoid Tirz and Reta on the same day because spacing makes it simpler to notice how each one feels on its own. With two Tirz pins already in the week that means spreading three shots out instead of bunching them.

PatientHarbour23archiveApr 17
↳ replying to @SharpCinder28

Thanks, good to know. What reta amount are you using next to that? You’re right that separating them lets you tell the sides apart. I already know my tirz pattern but this is my first time with reta so keeping them apart makes sense. I was leaning toward reta tomorrow, tirz Sunday night, then reta again Wednesday morning, but maybe a rotating Friday Monday Thursday Sunday pattern would be better.

SlowThistle36archiveApr 17

I do my 2.5 tirz on Fridays for weekend appetite control and the new 1 mg reta on Mondays. So far it’s working with no nausea or strange effects.

SharpCinder28archiveApr 17
↳ replying to @PatientHarbour23

Still low at 2 mg. Right now the stack is reta plus a couple other glp items at 1 mg, 4 mg tirz, and 2 mg reta.

PatientHarbour23archiveApr 17
↳ replying to @SlowThistle36

Thanks, I like Friday for the weekend effect so I might copy that and start reta on Monday. Not familiar with that other stack but I’ll look into it.

ClearWillow59archiveApr 17
↳ replying to @PatientHarbour23 (opening post)

I used to space them three days apart on different days so tirz day one, reta day two, skip, then tirz again. That helped with weight loss. I checked the schedule on a plotter tool to see how it looked. Now that I’m looking for maintenance I stretched it to every four days with a skip day between each and that’s working fine too.

CopperSignal27archiveApr 17

Tirz 4.25 mg and reta 1.4 mg every other day, which comes to about 15 mg tirz and 5 mg reta weekly. I started that way and never changed; I suspect larger less frequent doses would give me more sides.

IronBramble31archiveApr 17

For maintenance I’ve been doing 1 mg of each 3.5 days apart. Since you’re hitting two of the three receptors, more time between shots might be better. Both tirz and reta have roughly 5–6 day half lives and reactions vary. I gained a bit after surgery but once I’m back I want to try 4–5 days apart at 1.5 mg each just to test it.

PlainAnchor84archiveApr 17
↳ replying to @ClearBeacon24

Delivery issues forced me to change my pinning days. Now I do 5 mg tirz on Friday and 8 mg reta on Monday. After a month I’ll stop the tirz to see if the reta needs raising.

WryHarbour76archiveApr 17

I do 5 mg tirz on Tuesday and 1.5 mg reta on Saturday. I used a tracking app to test different timings so the peaks would alternate.

PatientHarbour23archiveApr 17
↳ replying to @ClearWillow59

Thanks. I don’t want worse sides so I’m not rushing higher doses. Team post-surgery weight gain here too. I did tirz this morning, will do reta Monday, then tirz Thursday and reta Sunday to see how it feels. I’m also trying to alternate the doses over time since reta may become the main one later. I used the app this morning to set two days between each shot: tirz today, reta Monday, tirz Thursday, reta Sunday. After a few rounds I’ll check the graphs and tweak.

WryHarbour76archiveApr 17
↳ replying to @PatientHarbour23

I was splitting tirz twice a week when I added reta and split that too, which started to feel like too many shots. Over about three weeks I adjusted the morning and evening times and shifted days in the app until I landed on one tirz and one reta per week. The graph shows I could probably fine-tune the peaks to alternate more exactly but I’m happy for now.

WryHarbour76archiveApr 17
↳ replying to @PlainKettle23

It’s called Shotsy and the basic version is free. I liked it enough that I paid for the upgrade; first app this 54-year-old has ever paid for.

PlainKettle23archiveApr 17
↳ replying to @WryHarbour76

I’ve been using Dose Track but it’s not very user-friendly and my stack hasn’t changed much yet. I’ll start a recomp stack in a week so that’s a good time to try something else. Thanks.

CopperBeacon48archiveApr 17

This isn’t one-size-fits-all; you have to test and note when food noise and hunger return with each dose because everyone reacts differently. Every six days for each peptide has worked best for me with no sides, so start at a milligram level that fits your body. I’ll share my plan only as an example, not to copy. It takes time to figure out what suits you personally. I keep everything in one place with an Outlook calendar so I get reminders the day before and on the day.

PatientHarbour23archiveApr 17
↳ replying to @PlainKettle23

It really is helpful and I also paid for it once I started using it. I began tirz on a split schedule, three times a week at Sun midday, Tues evening, and Fri morning until about two months ago when I got my first reta vial right before shoulder surgery. I just mixed that yesterday. I moved to Monday night and Friday morning to space things out and didn’t notice the peaks and valleys I expected. I pinned tirz this morning and plotted adding reta starting Monday morning, basically Monday reta, Thursday tirz, Sunday reta, Wednesday tirz. I’m starting reta at 0.5 on purpose and will move to 1 after a few pins. Before surgery my tirz was around 9 mg per week at 3 per pin; now I’m moving toward about 3.5 per tirz pin plus maybe 1 for reta.

PatientHarbour23archiveApr 17
↳ replying to @CopperBeacon48

That’s a good idea; I might add that along with the app. I already track sides but need to start watching the noise more closely.

ClearCinder63archiveApr 18

I pin both on Friday mornings: 2 mg tirz and 1.5 mg reta. I’ve considered staggering to alternate the peaks but the current way feels fine and helps me not overeat on weekends. It works for me though everyone is different.

GreyThistle97archiveJun 3

Just wanted to say thanks. I’ve been on 15 mg tirz for about a year. I pinned my first 2 mg reta yesterday and plan to keep tirz at half or one-third my usual amount (7.5 or 5) while staggering days. I’ve seen others who were on high-dose tirz go straight to higher reta and drop tirz, but I want to keep some tirz for food noise. Maybe not a useful post but thanks for asking and answering the questions I had.

ClearWillow59archiveJun 4

I pin separately every four days, staggering two days so tirz day one, reta day three, tirz day five and so on, which means I pin every other day.

BrightBeacon40archiveJun 4
↳ replying to @PatientHarbour23 (opening post)

I haven’t heard of alternating tirz and reta. What’s the advantage?

ClearLedger24archiveJun 4
↳ replying to @BrightBeacon40

I’m thinking of trying it. Split dosing reduces the chance of food noise returning in the last days before the next shot. Tirz is also said to suppress hunger more strongly than reta, so this could let both doses stay lower while still maximizing weight loss.

NorthSparrow39archiveJun 4

I’ve been doing tirz every five days and just dropped from 7.5 mg to 5 mg because of injection site reactions at the higher amount. My reta arrived this week so I took the first 2 mg on the same day as tirz. I’m feeling fine so I think I’ll keep both on the same day every five days.

GreyThistle97archiveJun 4
↳ replying to @ClearWillow59

Do you mind sharing how much of each you pin? Did you start smaller and work up? Any sides?

GreyThistle97archiveJun 4

I’ve been on GLP-1s for over three years, two-plus years at the top sema dose before switching to 15 mg tirz weekly for about a year. I always do a little routine to keep things moving with psyllium and a colon cleanse mix. I took my first 2 mg reta a few days ago at the usual tirz time but chose reta only to ease in. I did the psyllium drink last night and had an epic stomach ache for about twelve hours. I’m not new to these meds but this didn’t happen on tirz or sema, and it was eleven days after my last tirz so it was definitely the reta. Everything settled eventually but it was rough. Makes me think the reta is really working, but word to the wise if anyone has a strong reaction with that.

SharpTimber40archiveJun 4

I take a full tirz dose at once but split reta into two weekly shots: 7.5 mg tirz on Thursday, 1.5 mg reta on Saturday, and 1.5 mg reta on Tuesday. I get an elevated heart rate I dislike with reta so splitting helps, and I think it’s better not to take both on the same day.

PlainTimber78archiveJun 4

I do 6 mg reta Saturday morning and 7.5 mg tirz Tuesday evening.

ClearWillow59archiveJun 4
↳ replying to @GreyThistle97

Sure. I started micro-dosing every other day with 0.7 tirz and added 0.25 reta each time, effectively alternating daily. Later I moved to every three days each staggered, then settled at every four days so I pin every other day alternating. Highest was 1.2 of each, equaling 2.325 mg per week of each or 4.65 mg total weekly. I lost 52 lb over a year and the loss improved after adding reta. Now I’m at 0.9 and 1.1 trying to find maintenance. Why pin so often? Same reason I drink coffee every morning instead of fourteen coffees on Monday. I worked this out after checking doses and schedule on the plotter tool. It helps to see the peaks, valleys, and how they interact.

PatientBeacon95archiveJun 4

A friend takes 13 mg tirz and 3 mg reta the same day because I administer it for her since her family is uneasy about it. She’s had zero sides on GLP-1s. We discussed splitting but she’s been fine on the same day. Down 60 lb in seven months from 300 to 240 with no loose skin so far.

PatientHarbour23archiveJun 4
↳ replying to @BrightBeacon40

Basically you get the extra food-noise control from tirz plus the overall GLP benefits from reta.

GreyThistle97archiveJun 9
↳ replying to @PatientBeacon95

That’s a pretty high tirz amount with the reta, right? I was on 15 mg weekly for a long time but wanted to be cautious so I cut to 7.5 mg when I added 2 mg reta last week. A little over a week now and so far so good. Thanks for sharing your friend’s experience.

PatientBeacon95archiveJun 9
↳ replying to @GreyThistle97

It’s a bit aggressive but no sides and it keeps her IBS in check. She’s still losing and feels healthier; her heart rate is better now that she weighs less even on reta. I don’t know what happens when she plateaus. Hoping to hear more about stacking. Reta doesn’t work for me because of too much heart-rate increase and it seems to dehydrate me no matter how much I drink.

GreyThistle97archiveJun 19
↳ replying to @PatientBeacon95

Thanks, interesting to see how others handle it. I’ve increased reta fairly quickly to 4 mg in week two (2 mg twice that week) and 3 and 3 this week. No big problems so far except food noise is louder on just 7.5 tirz. I’m dropping weight fast and feel like I’m keeping muscle, which is the goal. Good luck to your friend.

RustAnchor35archiveJul 18

I messed up and took both on the same day once. Ended up with diarrhea and stomach pain.

GreyTimber24archiveJul 18

Random question since this seems like the right place: why stack tirz and reta instead of just using one?

IronKettle95archiveJul 18
↳ replying to @GreyTimber24

The first one really cuts down my hunger levels while the second supports fat loss even though it doesn't handle cravings nearly as well. My schedule has me using 7.5 milligrams of the initial compound every Friday plus 4 milligrams of the other one on Tuesdays to add extra support. If I relied on either compound by itself I would still inject on two days each week or switch to spacing shots five or six days apart.

GreyTimber24archiveJul 18
↳ replying to @IronKettle95

Thanks. I’ve been using a five-day schedule just to shift the dosing day to one with less going on. Not sure if I’ll keep it. Do you split to avoid losing appetite suppression on the last days?

IronLedger90archiveJul 18
↳ replying to @PatientHarbour23 (opening post)

Alternate. 4 mg reta Monday night, 2 mg tirz Thursday night.

IronKettle95archiveJul 18
↳ replying to @GreyTimber24

Correct. Tirz half-life is about five days and reta about six. Some titrate up to cover the final couple days of the week; others just push through or shorten the cycle and pin twice weekly.

GreyHarbour68archiveJul 18

I’ve found 3 mg tirz Monday and Friday plus 3 mg reta Wednesday works better for me than 10–12 mg tirz alone. The main difference is food-noise suppression; the combo controls appetite and cravings far better. Retatrutide by itself is awful for me though, with anhedonia and an uncomfortable dopamine effect and little impact on food noise. Combining them has been the secret for me and the balance feels far better than either alone.

AmberCinder46archiveJul 18
↳ replying to @GreyHarbour68

That’s close to my stack: tirz Monday and Friday, reta Wednesday and Sunday. It works well without big swings in appetite or bad sides.

RustAnchor35archiveJul 18

I’ll have to try three to four days apart to see if that lowers sides. What’s the lowest tirz dose you’ve found that still suppresses appetite?

AmberCinder46archiveJul 18
↳ replying to @RustAnchor35

I lost 10 lb in four weeks on the 2.5 starter dose. The next two months 5 mg was working fine.

GreyBeacon50archiveJul 18

Alternate with 3.5 days between shots: 7 mg tirz Friday morning and 2.5 mg reta Monday night.

PatientPebble79archiveJul 18
↳ replying to @SharpTimber40

I take them at the same time but at much lower amounts. Sliding into maintenance now with 1 mg tirz and 1 mg reta weekly. I expect a slow continued loss like a pound a month, which is fine. I didn’t push the weight-loss phase all the way so I can afford a bit more if that’s how it goes. I’m fascinated by the variety in doses and timing and glad so many have individualized it. A regular reta regimen would be too much for me and going higher on tirz would have been wasteful and probably not well tolerated. My highest tirz was 2.5 and felt fine, but my highest reta at 4 was deeply unpleasant.

QuietLantern17archiveJul 18

I’m trying to titrate down to minimal tirz and mainly use reta. Currently at 10 mg tirz and 3 mg reta both Sunday night before bed. Tomorrow I’ll move to 7.5 mg tirz and 4 mg reta for the next four weeks. I also take 2.4 mg cagri on Monday for appetite. Nothing has changed yet so I’m eager to raise reta. No sides except I get cold easily, which I don’t mind in summer.

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Those who stack Reta and Tirz—do you pin same time or alternate? · ZyraTrack Community