Going from Tirzepatide to Reta

[Venne]

I would like to switch from Tirzepatide to Reta.
My goal is to avoid any further muscle loss and hopefully try to get back some of what I already lost on Tirz.

Any tips on how to calculating equivalent dose of Reta coming from 15mg (Zepbound) once a week?
Is there a chart somewhere? Some rule of thumb, or should I just start at min dose Reta and titrate back up?

Tips and advice of recommended stacks that work well with Reta.

 

[WholesomeApril]

Sorry to break it to you but Reta isn’t going to help you gain muscle back. You can do that without going thought the hassle of switching (switching from a large triz dose is a process)

Just cut your current dose of triz back so you can start hitting your protein intake and picking up heavy things

 

[Venne]

Sorry to break it to you but Reta isn’t going to help you gain muscle back. You can do that without going thought the hassle of switching (switching from a large triz dose is a process)

Just cut your current dose of triz back so you can start hitting your protein intake and picking up heavy things

To be honest, I am not well versed in the ways of lifting heavy things. Where to start? What should an appropriate protein intake be?

 

[eidos]

There is no dose equivalence between Reta and Tirz because they do not have the same affinities for GLP-1 and GIP receptors. And Reta is a glucagon receptor agonist, whereas Tirz is not. So they’re really not comparable, to the point that some people, including myself, use both in combination (type 2 diabetes).

Start with small doses of Reta (1 to ~2 mg) to see what side effects it causes in you. Then continue to increase the dose in 4-week increments until a steady state is reached, so you can assess the results against your goals.
The latest meta-analysis on sarcopenia, or muscle loss, published a few weeks ago, recommends 1.2 grams of net protein per kilogram of body weight per day. The weight in kilograms to use is your target weight, not your current weight. Most modern scales display muscle mass and skeletal muscle mass. Use that as your guide (it will also help you determine whether your weight goal is realistic and doesn’t put your health at risk).

There’s no need to think about tough weight-training sessions if that’s not your cup of tea.
Do a few minutes of controlled eccentric movements with weights each day. Take breaks during your work and spend 3-4 minutes doing eccentric movements, resistance band exercises, wall sits, or similar exercises.

I even did them on the subway or the bus, anywhere whenever I had some time to kill, using the bars (I come from a family of firefighters, not pole dancers ;-) and did a few wall sits instead of using a seat.

 

[lessthanhalf]

I am just going to second that swapping from tirz to reta to better preserve muscle is not really supported by the studies.

Things that do make a difference is any kind of resistance exercise, and higher protein intake, I would have said 1.5g/kg of body weight but the poster above suggests 1.2, either would be fine.

While losing muscle mass during weight loss is not ideal, in practical terms it is not an issue at all, unless you are starting from a point of already being very low on muscle mass, and most overweight and obese people carry extra muscle, partly from the anabolic state of overnutrition and partly the demands of moving a heavier body. So losing some muscle with the fat has been shown to substantially improve everyday physical performance, when weight is lost with GLP's. as less muscle is needed to move around a body that weighs less. While I was losing weight from 115kg to 75 kg it was totally obvious to me walking up a hill that every 10 kilos I lost made a huge difference to the amount of effort required to get up that hill, despite losing some muscle along the way.

 

[Venne]

I am just going to second that swapping from tirz to reta to better preserve muscle is not really supported by the studies.

Things that do make a difference is any kind of resistance exercise, and higher protein intake, I would have said 1.5g/kg of body weight but the poster above suggests 1.2, either would be fine.

While losing muscle mass during weight loss is not ideal, in practical terms it is not an issue at all, unless you are starting from a point of already being very low on muscle mass, and most overweight and obese people carry extra muscle, partly from the anabolic state of overnutrition and partly the demands of moving a heavier body. So losing some muscle with the fat has been shown to substantially improve everyday physical performance, when weight is lost with GLP's. as less muscle is needed to move around a body that weighs less. While I was losing weight from 115kg to 75 kg it was totally obvious to me walking up a hill that every 10 kilos I lost made a huge difference to the amount of effort required to get up that hill, despite losing some muscle along the way.

I was basing that bit about muscle loss from this:

But I concede it is probably a moot point as the muscle loss is not horrific.

 

[Venne]

There is no dose equivalence between Reta and Tirz because they do not have the same affinities for GLP-1 and GIP receptors. And Reta is a glucagon receptor agonist, whereas Tirz is not. So they’re really not comparable, to the point that some people, including myself, use both in combination (type 2 diabetes).

Start with small doses of Reta (1 to ~2 mg) to see what side effects it causes in you. Then continue to increase the dose in 4-week increments until a steady state is reached, so you can assess the results against your goals.
The latest meta-analysis on sarcopenia, or muscle loss, published a few weeks ago, recommends 1.2 grams of net protein per kilogram of body weight per day. The weight in kilograms to use is your target weight, not your current weight. Most modern scales display muscle mass and skeletal muscle mass. Use that as your guide (it will also help you determine whether your weight goal is realistic and doesn’t put your health at risk).

There’s no need to think about tough weight-training sessions if that’s not your cup of tea.
Do a few minutes of controlled eccentric movements with weights each day. Take breaks during your work and spend 3-4 minutes doing eccentric movements, resistance band exercises, wall sits, or similar exercises.

I even did them on the subway or the bus, anywhere whenever I had some time to kill, using the bars (I come from a family of firefighters, not pole dancers ;-) and did a few wall sits instead of using a seat.

Thank you Kind Stranger.

I was fully expecting at least some sarcasm and/or light teasing for my ignorance regarding resistance exercise.
I found your reply to be shockingly helpful and it is greatly appreciated.

 

[lessthanhalf]

I was basing that bit about muscle loss from this:

But I concede it is probably a moot point as the muscle loss is not horrific.

I am allergic to watching anything medical that comes in video format, but despite the qualifications written on his shirt, he is not a suitable candidate to be using the drug, and not who it was designed for, and there is no scientific research on the use of GLP drugs in non overweight non diabetics. He is clearly not overweight so its use is not medically justifiable, regardless of the phd on his shirt. So its effects in someone who should not be taking it are not really evidence of anything that applies to people using the drug to treat obesity.

Muscle loss from GLP's is a real issue, but really only when you start out with sarcopenia or sarcopenic obesity, so an issue especially with much older persons at high risk of sarcopenia, or with severe chronic illness and obesity. Most obese persons carry above average amounts of muscle, even if unfit. And GLP drugs significantly improve muscle quality, reducing intramuscular fat and making it work more efficiently even if a bit smaller. And in practice the weight loss itself makes a vast difference to physical functioning.

 

[eidos]

I would have said 1.5g/kg of body weight but the poster above suggests 1.2, either would be fine.

I this paper, it was a minimum.

I'd like to add something important about protein intake. With Tirz and Reta, slowed gastric emptying causes all sorts of problems, from foul-smelling burps to consuming too much protein at once.
It’s important to know that for most people, 30g-35g of net protein per meal is the maximum that can be digested at one time. This amount may be slightly higher for very heavy or very muscular individuals. Beyond that, excess amino acids, which the body cannot use to build protein, produce ammonia, then urea, or are converted into glucose or lipids (depending on the amino acid), or into ketone bodies. This is generally not what we want. We may see an increase in liver enzymes, which indicates metabolic stress. Sometimes it leads to chronic kidney disease requiring lifelong dialysis (I witnessed this with a couple of guys who worked out at the same gym as me in the ‘80s, though they were also taking testosterone, which didn’t help).

it was totally obvious to me walking up a hill that every 10 kilos I lost made a huge difference to the amount of effort required to get up that hill, despite losing some muscle along the way.

I gained 40 kilograms the year I turned 40. Some people were worried about it, while others tried to make me feel guilty.
I’ve told them that when I was 25, I had no problem walking 40 kilometers with a 40-kilogram backpack. The difference is that back then, in the morning, I could set the backpack down and rest.
I agree with you, gaining weight and getting rid of it is quite an experience. Every little victory counts and is really motivating. Right now, seeing the projected HbA1c on my CGM app is really encouraging. I’m even excited to have my next blood test.
🙂

 

[eidos]

I am allergic to watching anything medical that comes in video format, but despite the qualifications written on his shirt, he is not a suitable candidate to be using the drug, and not who it was designed for, and there is no scientific research on the use of GLP drugs in non overweight non diabetics. He is clearly not overweight so its use is not medically justifiable, regardless of the phd on his shirt. So its effects in someone who should not be taking it are not really evidence of anything that applies to people using the drug to treat obesity.

I agree with you. What’s more, he isn’t very transparent in the information he provides; I’ve noticed several flaws in his reasoning. The thing that seemed interesting to me is PCSK9. I checked, and there are no articles demonstrating a change in levels; I couldn’t find any articles citing this protein in the Reta studies.

In fact, what has been demonstrated is a decrease in LDL, not an increase. And I’ve already verified this in my blood tests. It’s possible that the increase in LDL he observed is idiosyncratic and stems from something other than Reta. But he doesn’t even consider that possibility, which makes him a poor scientist.

It’s mostly just sensationalism.

 

[lessthanhalf]

The effect of GLP drugs on lipids is pretty well documented, cannot say for certain it is the same for reta as for tirz and sema, but it is very likely, and they do reduce LDL and risk of heart attack and stroke etc.

 

[lessthanhalf]

I this paper, it was a minimum.

I'd like to add something important about protein intake. With Tirz and Reta, slowed gastric emptying causes all sorts of problems, from foul-smelling burps to consuming too much protein at once.
It’s important to know that for most people, 30g-35g of net protein per meal is the maximum that can be digested at one time. This amount may be slightly higher for very heavy or very muscular individuals. Beyond that, excess amino acids, which the body cannot use to build protein, produce ammonia, then urea, or are converted into glucose or lipids (depending on the amino acid), or into ketone bodies. This is generally not what we want. We may see an increase in liver enzymes, which indicates metabolic stress. Sometimes it leads to chronic kidney disease requiring lifelong dialysis (I witnessed this with a couple of guys who worked out at the same gym as me in the ‘80s, though they were also taking testosterone, which didn’t help).


I gained 40 kilograms the year I turned 40. Some people were worried about it, while others tried to make me feel guilty.
I’ve told them that when I was 25, I had no problem walking 40 kilometers with a 40-kilogram backpack. The difference is that back then, in the morning, I could set the backpack down and rest.
I agree with you, gaining weight and getting rid of it is quite an experience. Every little victory counts and is really motivating. Right now, seeing the projected HbA1c on my CGM app is really encouraging. I’m even excited to have my next blood test.
🙂

Protein intake is an interesting question seeing as I have been on a 40-50% of my calories protein diet for the past nearly 4 years. There is so little real research on longer term much higher protein intakes that I can find. In general lower rather than higher but still adequate protein intake is associated with longevity in animal models, but in humans there is some evidence that higher intakes can help prevent sarcopenia and reduce muscle loss with weight loss, and help with weight loss by reducing appetite. To actually get protein poisoning is nearly impossible requiring extremely low fat or carbohydrate intake. And low protein diets reduce the progression of renal failure.

I have had obesity related proteinuria for 30 years or so that nearly goes away if I lose weight, with no real evidence of progressive renal damage thankfully, but I was a bit concerned about that extreme a protein intake on renal function. In my case at least the proteinuria improved dramatically with weight loss from 145kg to 75 kg, so no evidence of renal damage from it , despite the very high protein intake.

And very high protein intake does help to control hunger. When I started losing the weight in 2022 I believed GLP's were impossibly expensive so had to lose the weight without them, and the diet was more or less low calorific density low fat and high protein with zero highly rewarding / high calorie / high glycemic index carb foods to try to prevent binge eating responses to those food types. Thankfully I now have access to cheap chinese GLPs that help with the hunger, but have stuck with the very high protein intake for its effects on controlling appetite, given a serious lifelong obesity problem I am reluctant to lose any advantage in controlling it.

 

[eidos]

The effect of GLP drugs on lipids is pretty well documented, cannot say for certain it is the same for reta as for tirz and sema, but it is very likely, and they do reduce LDL and risk of heart attack and stroke etc.

these results suggest that the GCGR agonism of retatrutide could lead to reduced circulating ANGPTL3/8 concentrations, which may then contribute to decreases in TG and LDL‐C levels.

link to NCBI: (https://pmc.ncbi.nlm.nih.gov/articles/PMC12409240/)

 

[eidos]

Protein intake is an interesting question seeing as I have been on a 40-50% of my calories protein diet for the past nearly 4 years. There is so little real research on longer term much higher protein intakes that I can find. In general lower rather than higher but still adequate protein intake is associated with longevity in animal models, but in humans there is some evidence that higher intakes can help prevent sarcopenia and reduce muscle loss with weight loss, and help with weight loss by reducing appetite. To actually get protein poisoning is nearly impossible requiring extremely low fat or carbohydrate intake. And low protein diets reduce the progression of renal failure.

I have had obesity related proteinuria for 30 years or so that nearly goes away if I lose weight, with no real evidence of progressive renal damage thankfully, but I was a bit concerned about that extreme a protein intake on renal function. In my case at least the proteinuria improved dramatically with weight loss from 145kg to 75 kg, so no evidence of renal damage from it , despite the very high protein intake.

And very high protein intake does help to control hunger. When I started losing the weight in 2022 I believed GLP's were impossibly expensive so had to lose the weight without them, and the diet was more or less low calorific density low fat and high protein with zero highly rewarding / high calorie / high glycemic index carb foods to try to prevent binge eating responses to those food types. Thankfully I now have access to cheap chinese GLPs that help with the hunger, but have stuck with the very high protein intake for its effects on controlling appetite, given a serious lifelong obesity problem I am reluctant to lose any advantage in controlling it.

At a rate of 30 grams every 2 hours over a 16-hour waking period, that comes to 240 grams per day. That leaves plenty of margin.

For most people, gastric emptying of protein takes about 1 to 1.5 hours, depending on how well it was chewed or whether it’s liquid protein. With liraglutide, I noticed that my stomach emptied after 4-6 hours. With Tirz and Reta, it’s more like 3 hours. I need to take that into account. But with Reta, it’s less of an issue: I rarely manage to eat more than 20 grams in a single meal.

When I consume too much of it, it produces sugar, which raises my blood sugar levels. It also increases glucagon secretion and causes the dawn phenomenon (blood sugar levels that start to rise on their own an hour before waking up; a surge in HGH is likely but has not been confirmed).

Another issue in my case (diabetes) is that branched-chain amino acids, such as leucine, although essential because our bodies cannot produce them, increase insulin resistance when their blood levels are too high.

The problem: doctors don’t have time to supervise this process. Everyone has to find their own sweet spot based on their health and goals. And no matter how hard we try to alter our metabolic balance, the body responds by maintaining homeostasis, reminding us that we can’t just do whatever we want. It’s a real marathon.

 

[Venne]

I this paper, it was a minimum.

I'd like to add something important about protein intake. With Tirz and Reta, slowed gastric emptying causes all sorts of problems, from foul-smelling burps to consuming too much protein at once.
It’s important to know that for most people, 30g-35g of net protein per meal is the maximum that can be digested at one time. This amount may be slightly higher for very heavy or very muscular individuals. Beyond that, excess amino acids, which the body cannot use to build protein, produce ammonia, then urea, or are converted into glucose or lipids (depending on the amino acid), or into ketone bodies. This is generally not what we want. We may see an increase in liver enzymes, which indicates metabolic stress. Sometimes it leads to chronic kidney disease requiring lifelong dialysis (I witnessed this with a couple of guys who worked out at the same gym as me in the ‘80s, though they were also taking testosterone, which didn’t help).

They took in so much protein it wrecked their kidneys?
Seems like there would be plenty of warning signs to pull back from doing permanent damage, did they just not care?

 

[eidos]

They took in so much protein it wrecked their kidneys?
Seems like there would be plenty of warning signs to pull back from doing permanent damage, did they just not care?

The first guy trained for two years and ended up looking like Stallone after getting stung by a swarm of bees. His progress impressed me: he could do one-armed pull-ups. I’ve never been able to do that.

We didn't see him for several months. Until one day, a short, obese depressed man showed up at the club. We all recognized him. That's when he told us he'd ruined his kidneys and was on dialysis. He wasn't even 20 years old.

One of the instructors also told me the story of the second guy I’d run into a couple of times. That's when the instructor explained the whole protein thing to me. I tend to believe him, since he had a bachelor's degree in physical education from the same university where I was studying biochemistry.