Transition from 15mg Tirz to Tirz+Reta dosage questions for obese male

TropicalBlaster

TropicalBlaster

Explorer
Joined
Jun 18, 2026
Messages
18
Reaction score
6
Location
Adelaide
Hey everyone,

34-year-old guy | 5'10

Background: I've dealt with obesity my entire life, caused by bad medical guidance from dietitians. From age 3 I was raised on a 'low fat' diet, which meant my meals were essentially sugar-based right up into my 20s. I don't think I began eating correctly until I was 25YO.

[Highest weight 155 kg (342 lbs) DEC 2019]

Weight at start 136 kg (300 lbs) JAN 2025

Weight now 110 kg (242 lbs) JUN 2026

Target weight 90 kg (198 lbs) DEC 2026

Right now I take 15 mg/week TIRZ, and food noise plus cravings are still present. I've just switched to a carnivore diet since that has reduced food noise for me before. My intention is to stay on Carnivore until I drop under 100 kg, after which I'll move to a calorie deficit.

I've bought RETA to add on, but I'm unsure how much TIRZ to reduce....

What I'm planning is 2x/week injections (TIRZ on Sunday, RETA on Wednesday)

  • 12.5 mg TIRZ plus 2mg RETA for 4 weeks; then,
  • 10 mg TIRZ plus 4mg RETA for 4 weeks; then,
  • 7.5mg TIRZ plus 6mg RETA until goal weight.

Has anyone been through something similar or can offer advice on this?

P.S. I also have GHK-CU on order and intend to use 2mg/day.

Edit: spelling
 
TropicalBlaster said:

Hey everyone,

34-year-old guy | 5'10

Background: I've dealt with obesity my entire life, caused by bad medical guidance from dietitians. From age 3 I was raised on a 'low fat' diet, which meant my meals were essentially sugar-based right up into my 20s. I don't think I began eating correctly until I was 25YO.

[Highest weight 155 kg (342 lbs) DEC 2019]

Weight at start 136 kg (300 lbs) JAN 2025

Weight now 110 kg (242 lbs) JUN 2026

Target weight 90 kg (198 lbs) DEC 2026

Right now I take 15 mg/week TIRZ, and food noise plus cravings are still present. I've just switched to a carnivore diet since that has reduced food noise for me before. My intention is to stay on Carnivore until I drop under 100 kg, after which I'll move to a calorie deficit.

I've bought RETA to add on, but I'm unsure how much TIRZ to reduce....

What I'm planning is 2x/week injections (TIRZ on Sunday, RETA on Wednesday)

  • 12.5 mg TIRZ plus 2mg RETA for 4 weeks; then,
  • 10 mg TIRZ plus 4mg RETA for 4 weeks; then,
  • 7.5mg TIRZ plus 6mg RETA until goal weight.

Has anyone been through something similar or can offer advice on this?

P.S. I also have GHK-CU on order and intend to use 2mg/day.

Edit: spelling
Click to expand...
Does that follow a pattern — like showing up on the final day or 2 before your next pin? If it does (and possibly even if it doesn't), the first thing to try is split-dosing: half the dose every 3.5 days, or another schedule such as a smaller amount every 5 days (you can experiment with https://glp1plotter.com ).

No two people are the same, but for most/many, retatrutide is considerably weaker than tirz when it comes to suppressing appetite. Its mechanism is more mysterious, yet it sounds like at minimum you're after strong suppression. Assuming tirzepatide isn't giving you constipation you can't tolerate, cagrilintide could be your best option once you've tried split-dosing. Read up on it carefully ... even a tiny bit produces big effects and side effects, and a tiny bit more is massively unpleasant, so titrate especially slowly.

After that, maybe a small amount of retatrutide, but not as the main driver.
 
Jrammi said:


If I may suggest, you should improve insulin resistance by going into and staying in ketosis by cutting out carbs, including fruits. A ketomojo meter will tell you exactly the level of ketosis that you are in. We are not designed to eat three meals a day, and sugar and other high glycemic foods are addictive like drugs.

Click to expand...
Click to expand...
Alternatively, you could go the complete other direction with a diet built around starch.

Either way, reta is something I really like. When it comes to losing weight, it performs the best, and that still holds in the research even after 2 years. It's possible tirz + elora will outperform reta in those studies, though that isn't guaranteed.

If it were me, I'd make the switch to reta gradually, using it alone as a monotherapy for a period, while layering tirz and reta together in the interim, similar to the approach you outlined above. After that, if more help is needed once you're at 8+ mg of reta, bring in cagri or elora on top of it.
 
Have your losses stalled at the 15mg dose, and do you have diabetes? Would you consider nudging your Tirz dose upward a bit?

I'm asking because a relative of mine had maxed out at 15mg of Turz, and for a stretch both her blood sugar and her weight were moving the wrong way. Long story short, after she gave me an earful for even mentioning it, I steered her toward the grey market, and she began adding 1mg of Tirz daily on top of her 15mg shot. It took 6 weeks, but she got headed back in the right direction. Whether that's the ideal approach for her, I can't say, though it's doing the job right now and there's room to increase later. Her diet is very clean, she cooks and walks a great deal. Given her diabetes and autoimmune issues, recommending Reta wasn't something I wanted to do. Have you thought about that option at all?



I'm not opposed to your plan. I've run it myself (non diabetic) and had great results. I began with 7.5mg Tirz plus 0.5mg Reta, and across 3 months I worked down to 4mg of Reta alone, dropping 23lbs during the final month. For certain people it works extremely well. My advice would be to ease in at 1mg for the first couple of weeks, then raise it gradually after that, so you learn how your body responds first.
 
I'd simply bump the Tirz up to 17.5mg. Keep it at that level, then introduce .5 or 1mg of Reta and gradually raise the Reta while leaving the Tirz unchanged.
 
Perhaps take a look at your diet. On carnivore without a glp, getting in enough food to keep your current weight should be difficult. Do you log your intake? My impression is that a few carnivores overdo it with butter and cream.

Also, reta gives me sugar and starch cravings, and low carb or carnivore was impossible for me while on it. I used to fast for multiple days, but now it forces me into small, frequent meals.
 
Back
Top