Adverse kidney effects?

[fattymckee]

I read somewhere that Reta is not recommended for those with chronic kidney disease but cannot seem to find a lot of information about it. Has anyone read anything similar?

I've been using 15mg of tirz for awhile and need to change things up due to no weight loss, but I am researching options. Thanks!

 

[Chili777]

Wow. I was literally just looking at the Phase 2 trial data, and they don't support a negative impact on the kidneys, in fact, Reta appears to have a larger positive effect than Tirz:

"Regarding kidney function with retatrutide, in phase 2 trials it also showed a marked decrease in UACR in both diabetic and non-diabetic patients. In an extremely unexpected finding, retatrutide INCREASED eGFR and Cystatin-C based GFR by 8-10ml/min in non-diabetics. This effect disappeared after the patients stopped the drug. Because of this there are ongoing studies to investigate effects on renal function in participants with overweight/obesity and chronic kidney disease with retatrutide with data expected to be released in late 2025 or early 2026. As of now there are no approved drugs that have shown such a large increase in GFR. This is a potentially groundbreaking discovery and unprecedented in modern medicine if Lilly is able to confirm this rise in GFR is real."

eGFR is an estimate of how much blood your kidneys filter per minute. In most medical situations:

• Higher eGFR = better filtration
• Lower eGFR = worse filtration

So, at face value, an increase sounds good, but context matters. It could also mean the kidneys are working too hard due to diabetes, high protein diet, or certain medications, or even a stress response. In the Phase 2 trials, this effect reversed after stopping the drug, suggesting it wasn’t kidney damage and no current approved drug has shown such a large increase in eGFR. The rise occurred alongside improvements in weight, inflammation, lipids, and UACR (a marker of kidney stress), so there were no signs of hyperfiltration injury in the trial data presented and both creatinine‑based and cystatin‑C‑based GFR increased, which makes a statistical artifact a less likely explanation.

I'm not a doctor (by a long stretch) , but I just happened to be looking at the trial data and using Gemini to help me analyze it. Your question was very good timing. If you have kidney disease, or some you know or love does, then I would discuss these trial findings with your/their doctor and see if he agrees with the interpretation of the data.

 

[fattymckee]

Wow. I was literally just looking at the Phase 2 trial data, and they don't support a negative impact on the kidneys, in fact, Reta appears to have a larger positive effect than Tirz:

"Regarding kidney function with retatrutide, in phase 2 trials it also showed a marked decrease in UACR in both diabetic and non-diabetic patients. In an extremely unexpected finding, retatrutide INCREASED eGFR and Cystatin-C based GFR by 8-10ml/min in non-diabetics. This effect disappeared after the patients stopped the drug. Because of this there are ongoing studies to investigate effects on renal function in participants with overweight/obesity and chronic kidney disease with retatrutide with data expected to be released in late 2025 or early 2026. As of now there are no approved drugs that have shown such a large increase in GFR. This is a potentially groundbreaking discovery and unprecedented in modern medicine if Lilly is able to confirm this rise in GFR is real."

eGFR is an estimate of how much blood your kidneys filter per minute. In most medical situations:

• Higher eGFR = better filtration
• Lower eGFR = worse filtration

So, at face value, an increase sounds good, but context matters. It could also mean the kidneys are working too hard due to diabetes, high protein diet, or certain medications, or even a stress response. In the Phase 2 trials, this effect reversed after stopping the drug, suggesting it wasn’t kidney damage and no current approved drug has shown such a large increase in eGFR. The rise occurred alongside improvements in weight, inflammation, lipids, and UACR (a marker of kidney stress), so there were no signs of hyperfiltration injury in the trial data presented and both creatinine‑based and cystatin‑C‑based GFR increased, which makes a statistical artifact a less likely explanation.

I'm not a doctor (by a long stretch) , but I just happened to be looking at the trial data and using Gemini to help me analyze it. Your question was very good timing. If you have kidney disease, or some you know or love does, then I would discuss these trial findings with your/their doctor and see if he agrees with the interpretation of the data.

Thank you! This is what I recently read as well, or something similar. But earlier I swear I read the opposite lol. So I was wondering if any of you all knew more about it too

 

[lessthanhalf]

Semaglutide and Tirzepatide are considered important treatments in chronic kidney disease , proven to slow down progression of renal failure, only second to SLGTi therapy and blood pressure control. Reta is not officially recommended yet as it is not approved, and I don't think the major studies that would show this for it are done yet, but it sounds promising.

 

[Chili777]

Semaglutide and Tirzepatide are considered important treatments in chronic kidney disease , proven to slow down progression of renal failure, only second to SLGTi therapy and blood pressure control. Reta is not officially recommended yet as it is not approved, and I don't think the major studies that would show this for it are done yet, but it sounds promising.

Right, they can't prescribe Reta and it's also Phase 2 trial data. Given the effect on eGRF, it wouldn't surprise me if they had another trial focusing on it. I don't know the source the OP's question, but if I had a chronic kidney condition, I don't think I'd make the decision to start it myself without medical advice specific to my condition.

 

[lessthanhalf]

A very large proportion of people with early or even intermediate levels of kidney disease do not even know they have it . And obesity induced kidney disease and obesity induced hyperfiltration and proteinuria are very common. I had a fair amount of proteinuria nearly 30 years ago, and I was concerned that this would be a major problem long term, but thankfully it got better any time I lost weight and does not seem to have caused much in the way of permanent damage. This is not always the case and obesity is now one of the more common causes of renal failure. But if you are obese and have not had urine protein levels checked then you are not going to know there is a problem. Chatgpt estimate of 10-30% in those with BMI of 40 or more.

If there is actual impairment of renal function then it is definitely a case of getting good specialist advice, and probably not a terrible idea if it is only hyperfiltration and proteinuria.
I would include getting urine protein checked as well as lipids and blood sugars and blood pressure in older persons with longstanding obesity. Even a small amount of proteinuria justifies statin and aspirin therapy independently of lipid levels. As it is a strong predictor of cardiovascular risk. GLP's are likely to prevent a lot of future cases of renal failure.

I think if it was stage 1 or 2 then reta is probably safe enough so long as you made certain to get renal function and protein checked a few months after starting it to make sure it is not getting worse, anything more significant relying on more proven therapies and professional advice would make more sense.