Understanding CKD stages
Chronic kidney disease affects how our body processes medications, including Mounjaro. Our kidneys filter waste products and excess fluid from our blood, but when they’re not working properly, medications can build up to harmful levels.
CKD is classified into five stages based on our estimated glomerular filtration rate (eGFR), a measure of how well our kidneys filter blood. Your stage helps determine whether Mounjaro is appropriate.
- Stage 1 (eGFR 90 or above): normal kidney function with some kidney damage. Mounjaro is typically safe with standard monitoring
- Stage 2 (eGFR 60-89): mildly decreased function. Usually safe with regular monitoring
- Stage 3a (eGFR 45-59): moderately decreased function. Requires closer monitoring; standard dosing often appropriate
- Stage 3b (eGFR 30-44): moderately to severely decreased function. Needs specialist input; may require dose adjustments
- Stage 4 (eGFR 15-29): severely decreased function. Requires nephrologist approval and careful monitoring
- Stage 5 (eGFR below 15): kidney failure. Generally not recommended; specialist assessment required
Most people with CKD stages 1-3 can use Mounjaro safely with appropriate monitoring.
How Mounjaro affects your kidneys
Unlike some medications that can directly damage the kidneys, Mounjaro doesn’t appear to cause kidney harm in most people. Research suggests it may actually provide some protective benefits.
A large study published in The Lancet found that people with type 2 diabetes taking tirzepatide had improved kidney function markers compared to those taking insulin. The medication appeared to reduce the risk of kidney disease progression.1
However, there are important considerations for people with existing CKD.
Dehydration risk
Mounjaro can cause nausea and reduced appetite, which may lead to dehydration. For people with CKD, maintaining proper hydration is essential for preserving kidney function.
Blood pressure changes
Weight loss from Mounjaro often improves blood pressure, which benefits kidney health. However, if you take blood pressure medications, your doses may need adjusting as you lose weight.
Blood sugar improvements
Better glucose control from Mounjaro can slow CKD progression, particularly for people with diabetic kidney disease.
Medication interactions
Some CKD medications may need dose adjustments as your weight and kidney function change. Your prescribing clinician should coordinate with your nephrologist throughout treatment.
Dosing adjustments for CKD
Most people with mild to moderate CKD can start Mounjaro at the standard dose of 2.5 mg once a week. However, your doctor may recommend modifications based on your CKD stage.
- Stages 1-3 CKD: standard dosing protocol typically appropriate, with more frequent monitoring than usual
- Stage 4 CKD: may start at standard dose but with very close monitoring, particularly for dehydration and medication interactions
- Stage 5 CKD: generally avoided unless under specialist nephrologist care
The dose escalation schedule may be slower for people with CKD. While the standard protocol increases the dose every four weeks, your doctor might extend this to six or eight weeks to monitor how your kidneys respond.
Your prescribing clinician should coordinate with your nephrologist to ensure your CKD medications remain appropriate as your weight changes. Blood pressure tablets, in particular, often need reducing as weight loss improves blood pressure control.
What monitoring do you need with CKD?
Taking Mounjaro with CKD requires more frequent monitoring than for people with normal kidney function. Your healthcare team should track several key markers.
- Kidney function tests: your eGFR and creatinine levels should be checked every 3-4 months initially, rather than the usual 6-12 months for stable CKD
- Hydration status: regular assessment for signs of dehydration, particularly during the first few months when nausea is most common
- Blood pressure monitoring: weekly home blood pressure checks, as your medication needs may change with weight loss
- Electrolyte levels: sodium, potassium, and other electrolytes should be monitored more frequently, particularly if you experience significant nausea or reduced appetite
- Medication review: regular assessment of all your medications, as doses may need adjusting with weight loss and changing kidney function
- Cardiovascular risk factors: CKD increases heart disease risk, so lipid and diabetes markers need monitoring alongside kidney function
Your GP should coordinate this monitoring with your kidney specialist. Don’t attempt to manage this independently; the interaction between CKD, weight loss, and multiple medications requires professional oversight.
Kidney-friendly nutrition on Mounjaro
Nutrition for CKD is more complex than general healthy eating advice. What’s recommended for most people may need modifying depending on your CKD stage and blood test results.
This section covers general principles, but you should work with a renal dietitian to get personalised advice based on your specific kidney function and blood results.
Getting the right amount of protein
Protein is important for maintaining muscle mass and supporting recovery. However, people with CKD need to be more careful about how much protein they eat than the general population.
Too much protein can increase the workload on the kidneys, potentially accelerating CKD progression. Too little can lead to muscle wasting, particularly when you’re also losing weight on Mounjaro.
For most people with CKD stages 1-3, moderate protein intake is appropriate. Good sources include chicken, turkey, fish, eggs, and Greek yoghurt. Your renal dietitian can advise on the right amount for your stage of kidney disease.
Managing potassium
As kidney function declines, the body becomes less efficient at removing potassium from the blood. High potassium levels can cause dangerous heart rhythm problems.
This doesn’t mean avoiding all potassium-rich foods. In earlier stages of CKD, potassium levels are often fine. But if your blood tests show elevated potassium, you may need to limit foods like bananas, oranges, potatoes, and tomatoes.
Your dietitian can help you understand which foods to moderate based on your individual blood results, not a generic list.
Reducing sodium
Reducing salt intake helps manage blood pressure and reduces fluid retention, both of which are important for kidney health. Aim for less than 6g of salt a day.
In practice, this means cooking from scratch where possible, checking labels for sodium content, and limiting processed foods, ready meals, and takeaways. Herbs, spices, lemon juice, and garlic can add flavour without adding salt.
Staying hydrated
Hydration is particularly important when taking Mounjaro with CKD. The nausea and reduced appetite that Mounjaro can cause increase the risk of dehydration, which can worsen kidney function.
Aim for small, frequent sips of water throughout the day. If you’re struggling with nausea, try ginger tea or adding a small amount of lemon to water. Contact your healthcare team if you can’t keep fluids down for more than 24 hours.
Some people with advanced CKD may need to restrict fluid intake. Follow your nephrologist’s guidance on this rather than general hydration advice.
Eating well when your appetite is reduced
Mounjaro reduces appetite, which can make it difficult to eat enough to meet your nutritional needs. This matters more with CKD because malnutrition is a recognised complication of kidney disease.
Focus on nutrient-dense foods rather than large volumes. Smaller, more frequent meals may be easier to manage than three large ones. Prioritise protein and vegetables at each meal, even if portions are smaller than usual.
Staying active with CKD
Physical activity is beneficial for people with CKD. It can help manage blood pressure, improve cardiovascular fitness, maintain muscle mass, and support mental health, all of which are relevant when living with kidney disease.
However, many people with CKD experience fatigue that can make exercise feel difficult. The key isn’t hitting specific targets but building small, consistent habits that become part of your routine.
Research on habit formation suggests it takes an average of 66 days for a new behaviour to become automatic, though this varies widely between individuals.3 Starting with something small enough that you can do it even on a bad day gives the habit the best chance of sticking.
Practical starting points
A 10-minute walk after dinner is a good starting point. It’s low-intensity, doesn’t require special equipment, and attaching it to an existing routine (dinner) makes it easier to remember.
As this feels manageable, you can gradually do a little more. Some people find gentle swimming helpful because it’s easy on the joints and supports circulation without putting strain on the body.
Resistance training
Muscle wasting is common in CKD, and weight loss from Mounjaro can sometimes accelerate this. Resistance training, even using bodyweight exercises or light resistance bands, can help preserve muscle mass.
If you’re new to resistance training, ask your GP or a physiotherapist for guidance on safe exercises for your current fitness level. Even two short sessions a week can make a meaningful difference to muscle preservation.
Listening to your body
Exercise capacity can fluctuate with CKD. Some days you’ll feel fine; other days fatigue may be overwhelming. That’s normal. Doing something is always better than doing nothing, even if ‘something’ is a five-minute walk around the house.
NHS guidelines recommend 150 minutes of moderate activity a week for general health, but this is a background goal, not a target you need to hit immediately. Any movement is a step in the right direction.
NHS guidance and eligibility
NHS England guidelines for GLP-1 medications in people with CKD emphasise the importance of specialist input. While Mounjaro isn’t specifically contraindicated for most people with CKD, accessing it through the NHS requires meeting specific criteria.
NHS eligibility
- BMI of 40 or above with weight-related health problems, or BMI of 30 or above with type 2 diabetes
- Evidence of previous weight-loss attempts
- No contraindications to treatment
- Willingness to engage with lifestyle support
Private prescription considerations
If you don’t meet NHS criteria, private prescriptions are available. However, ensure your private prescriber reviews your complete CKD history, coordinates with your nephrologist, provides appropriate monitoring schedules, and has experience with CKD patients.
Many private providers won’t prescribe to people with stage 4-5 CKD due to the complexity of monitoring required.
Mounjaro clinical data
| Feature |
Mounjaro (tirzepatide) |
| Drug class |
Dual GLP-1/GIP receptor agonist |
| How it’s taken |
Once-a-week injection |
| Average weight loss |
Up to 26% after two years (SURMOUNT-4)4 |
| Dosing range |
2.5 mg to 15 mg once a week |
| CKD stages 1-3 |
Generally safe with appropriate monitoring1 |
| CKD stages 4-5 |
Requires specialist assessment; not generally recommended without nephrologist approval |
| Kidney function impact |
Improved kidney function markers in type 2 diabetes studies1 |
| Main CKD-specific risk |
Dehydration from nausea and reduced appetite |
| Monitoring frequency (CKD) |
Every 3-4 months initially, more frequent than standard CKD monitoring |
| UK availability |
NHS (with eligibility criteria) and private prescription |
Frequently asked questions
Will Mounjaro make my kidney disease worse?
Current research suggests Mounjaro doesn’t worsen kidney function and may provide some protection, particularly for people with diabetic kidney disease.1 However, proper monitoring is essential to ensure your individual response is positive.
The main risk is dehydration from side effects, which can temporarily affect kidney function if not managed.
What should I do if I become dehydrated from nausea?
Dehydration is the primary risk for people with CKD taking Mounjaro. Start with small, frequent sips of water throughout the day. If you can’t keep fluids down for more than 24 hours, contact your healthcare team.
Your nephrologist may want to check your kidney function and electrolytes if you’ve had a period of significant nausea or vomiting.
How will weight loss affect my other CKD medications?
Weight loss often improves blood pressure and blood sugar control, which may mean you need lower doses of related medications. Blood pressure tablets are the most commonly adjusted. Your healthcare team should review all your medications regularly and adjust doses proactively rather than waiting for problems.
Can I take Mounjaro if I’m on dialysis?
This requires a specialist nephrologist assessment. Some people on dialysis can use Mounjaro, but the monitoring requirements are complex, and not all providers will feel comfortable prescribing it. Speak to your kidney specialist about whether it’s an option for you.
What about kidney transplant recipients?
People with kidney transplants need specialist input from their transplant team before starting any new medication, including Mounjaro. The interaction with anti-rejection medications requires careful consideration and close monitoring.
Do I need to change my diet differently to someone without CKD?
Yes. People with CKD may need to manage their intake of protein, potassium, phosphorus, and sodium in ways that differ from general healthy eating advice. What’s appropriate depends on your CKD stage and blood test results.
Ask your GP for a referral to a renal dietitian who can give you personalised guidance.
Is it safe to exercise with CKD while taking Mounjaro?
For most people with CKD, physical activity is safe and beneficial. It helps manage blood pressure, supports cardiovascular health, and preserves muscle mass. Start with small amounts and build gradually. If you have advanced CKD or other complications, check with your nephrologist before starting a new exercise routine.
Why doesn’t Second Nature accept people with CKD?
Second Nature doesn’t currently accept people with CKD because the level of medical monitoring required exceeds what the programme can provide. People with CKD need coordination with nephrology services, more frequent kidney function tests, and specialist oversight for dose adjustments.
The safest approach for CKD patients is management through NHS services or private providers with specialised kidney expertise.
Can Mounjaro slow down CKD progression?
There’s emerging evidence that weight loss and improved blood sugar control from GLP-1 medications may help slow CKD progression, particularly in people with diabetic kidney disease.1 However, this research is still developing, and Mounjaro isn’t licensed specifically for kidney protection.
Speak to your nephrologist about the potential benefits in your specific situation.
What CKD stage is too advanced for Mounjaro?
There’s no absolute cut-off, but most clinicians are comfortable prescribing Mounjaro for CKD stages 1-3 with appropriate monitoring. Stage 4 requires very careful assessment by a nephrologist.
Stage 5 (kidney failure) generally means Mounjaro isn’t recommended unless under very close specialist supervision. The decision depends on your overall health, other medications, and the risk-benefit balance.
Why Second Nature doesn’t currently accept CKD patients
At Second Nature, we don’t currently accept people with CKD onto our Mounjaro programme. This isn’t because the medication is unsafe for CKD patients; it’s because the level of medical monitoring required exceeds what we can provide through our current programme structure.
People with CKD need:
- More frequent kidney function monitoring than standard protocols allow
- Coordination with nephrology services
- Complex medication interaction management
- Specialist oversight for dose adjustments
Our programme is designed for people who can safely use Mounjaro with standard monitoring. For people with CKD, the safest approach is management through NHS services or private providers with specialised kidney expertise.
This may change as our medical capabilities expand, but currently we prioritise patient safety by ensuring appropriate specialist oversight for complex conditions.
Take home message
You can take Mounjaro if you have chronic kidney disease, but only with proper medical supervision and coordination between your healthcare providers.
People with mild to moderate CKD (stages 1-3) can often use Mounjaro safely with appropriate monitoring, while those with more advanced disease need specialist assessment.
Nutrition requires more thought with CKD than for the general population. Protein, potassium, sodium, and hydration all need managing based on your individual blood results, ideally with guidance from a renal dietitian.
Building small movement habits can support your kidney health, cardiovascular fitness, and muscle mass. Start with what feels manageable and build from there.
If you have CKD and want to explore Mounjaro, speak to your GP about referral to a service that can provide the specialist monitoring you need.
While Second Nature doesn’t currently accept people with CKD onto our medication programme, our approach to weight management is built on the same principles that benefit kidney health: balanced nutrition, regular physical activity, and sustainable habit change.
In a 2025 study published in JMIR Formative Research, active subscribers on Second Nature’s semaglutide-supported programme achieved an average weight loss of 19.1% at 12 months, with 77.7% achieving at least 10% weight loss.5
Second Nature's Mounjaro and Wegovy programmes
Second Nature provides Mounjaro or Wegovy as part of our Mounjaro and Wegovy weight-loss programmes.
Why choose Second Nature over other medication providers, assuming you're eligible?
Because peace of mind matters.
We've had the privilege of working with the NHS for over eight years, helping people across the UK take meaningful steps toward a healthier, happier life.
Our programmes are designed to meet people where they are, whether that means support with weight loss through compassionate one-to-one health coaching, or access to the latest weight-loss medications (like Mounjaro and Wegovy) delivered alongside expert care from a multidisciplinary team of doctors, psychologists, dietitians, and personal trainers.
At the heart of everything we do is a simple belief: real, lasting change comes from building better habits, not relying on quick fixes. We're here to support that change every step of the way.
With over a decade of experience, thousands of lives changed, and a long-standing record of delivering programmes used by the NHS, we believe we're the UK's most trusted weight-loss programme.
We hope to offer you something invaluable: peace of mind, and the support you need to take that first step.
References
- Heerspink, H.J.L. et al. (2022). Effects of tirzepatide versus insulin glargine on kidney outcomes in type 2 diabetes. The Lancet Diabetes & Endocrinology, 10(11), 774-785.
- Kidney Care UK. (2024). General election 2024: kidney disease in the UK.
- Lally, P. et al. (2010). How are habits formed: modelling habit formation in the real world. European Journal of Social Psychology, 40(6), 998-1009.
- Aronne, L.J. et al. (2024). Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity: the SURMOUNT-4 randomized clinical trial. JAMA, 331(1), 38-48.
- Richards, R. et al. (2025). A remotely delivered GLP-1RA-supported specialist weight management program in adults living with obesity: retrospective service evaluation. JMIR Formative Research, 9(1), e72577.
