Understanding CKD stages
Your CKD stage determines how safely you can use Mounjaro and how closely you need to be monitored.
Kidneys filter waste products and excess fluid from the blood, and when they’re not working properly, some medications can build up to harmful levels.
CKD is classified into five stages based on your estimated glomerular filtration rate (eGFR), which measures how well your kidneys filter blood.
- 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 is often appropriate
- Stage 3b (eGFR 30-44): moderately to severely decreased function. Needs specialist input; may require a slower dose escalation
- 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
The Mounjaro Summary of Product Characteristics (SmPC) doesn’t require dose adjustments based on kidney function, but clinical experience in people with severe renal impairment and kidney failure is limited, so caution is advised at later stages.3
How Mounjaro affects your kidneys
Tirzepatide itself isn’t cleared by the kidneys in a way that causes direct toxicity, and in people with type 2 diabetes, it appears to slow the progression of kidney disease rather than accelerate it.1
The main CKD-specific risks come from the side effects of the medication and its effects on other parts of your body, rather than from the drug acting on the kidneys directly.
Dehydration and acute kidney injury
Mounjaro commonly causes nausea, vomiting, and reduced appetite, particularly during dose increases.
If these side effects lead to significant fluid loss, blood flow to the kidneys can drop, which can cause acute kidney injury (AKI).
People with existing CKD are more vulnerable to AKI than the general population, and repeated AKI episodes can worsen underlying kidney function.
Warning signs of dehydration or AKI to watch for include producing much less urine than usual, dark or concentrated urine, dizziness when standing up, persistent thirst, confusion, or unusual drowsiness.
If you can’t keep fluids down for more than 24 hours, or you notice any of these symptoms, contact your healthcare team.
Blood pressure changes
Weight loss on Mounjaro often improves blood pressure, which benefits kidney health.
If you take antihypertensive medication, your doses may need to be reduced as you lose weight to prevent your blood pressure from dropping too low.
Blood sugar improvements
Better glucose control can slow CKD progression, particularly for people with diabetic kidney disease. This is one of the reasons tirzepatide may have kidney-protective effects in people with type 2 diabetes.1
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
The SmPC doesn’t specify different starting doses for people with CKD, so most people begin at 2.5 mg once a week regardless of kidney function.3
However, your prescriber may recommend modifications to your titration based on your CKD stage and how you tolerate the medication.
- Stages 1-3 CKD: standard dosing protocol typically appropriate, with more frequent kidney function monitoring
- Stage 4 CKD: standard starting dose with very close monitoring, particularly for dehydration, AKI, and medication interactions
- Stage 5 CKD: generally avoided unless under specialist nephrologist care
The standard dose-escalation schedule increases the dose every 4 weeks.
For people with CKD, your prescriber might extend this to six or eight weeks to monitor how your kidneys respond and to reduce the risk of side effects that could trigger dehydration.
Blood pressure tablets, in particular, often need to be reduced as weight loss improves blood pressure control. Your prescribing clinician should coordinate with your nephrologist to regularly review all your medications.
What monitoring do you need with CKD?
Taking Mounjaro with CKD requires more frequent monitoring than standard protocols. 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 (fat) and diabetes markers need monitoring alongside kidney function
Your GP should coordinate this monitoring with your kidney specialist. The interaction between CKD, weight loss, and multiple medications needs 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 to be modified 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. 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 heart rhythm problems.
This doesn’t mean avoiding all potassium-rich foods. In earlier stages of CKD, potassium levels are often fine.
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.
Managing sodium intake
Having a sensible amount of salt in the diet helps manage blood pressure and reduces fluid retention, both of which are important for kidney health. We recommend seasoning whole foods to taste; if it tastes too salty, adjust for next time.
We recommend limiting ultra-processed foods as much as possible as they contain extremely high sodium levels and its difficult to manage salt intake if our diet is mainly made up of ultra-processed foods.
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 or trigger AKI.
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.
In CKD, this risks protein-energy wasting, a recognised complication that affects muscle mass and overall health.
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 helps manage blood pressure, improve cardiovascular fitness, maintain muscle mass, and support mental health, all of which are relevant for people living with kidney disease.
Many people with CKD experience fatigue that can make exercise feel difficult. We recommend starting by 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.4
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 help to maintain muscle mass.
Listening to your body
Exercise capacity can fluctuate with CKD. Some days you’ll feel fine; other days, fatigue may be overwhelming.
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.
NHS guidance and eligibility
NHS access to Mounjaro for obesity is being rolled out in phases through primary care. Eligibility criteria for the current phase are strict and prioritise people with the highest clinical need.5
NHS eligibility for Mounjaro (obesity)
- BMI of 40 or above, or 37.5 or above for people from South Asian, Chinese, other Asian, Middle Eastern, Black African, or African-Caribbean backgrounds
- At least 4 of the following 5 qualifying conditions: type 2 diabetes, hypertension, dyslipidaemia, obstructive sleep apnoea, or established cardiovascular disease
- Engagement with a behavioural support programme alongside the medication
- Minimum 5% weight loss at 6 months to continue treatment
CKD isn’t one of the qualifying conditions for NHS access, but many people with CKD also have type 2 diabetes, hypertension, or dyslipidaemia, which may make them eligible through those pathways.
Whether your GP practice participates in NHS Mounjaro prescribing varies by Integrated Care Board.
Private prescription considerations
If you don’t meet NHS criteria, private prescriptions are available.
Make sure 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 because of the complexity of monitoring required.
Mounjaro use by CKD stage
| CKD stage |
eGFR (ml/min/1.73m²) |
Mounjaro approach |
Monitoring |
| Stage 1 |
≥90 with kidney damage |
Standard dose and titration |
Every 6 months |
| Stage 2 |
60-89 |
Standard dose and titration |
Every 6 months |
| Stage 3a |
45-59 |
Standard dose with closer oversight |
Every 3-4 months |
| Stage 3b |
30-44 |
Standard dose, consider slower titration |
Every 3 months |
| Stage 4 |
15-29 |
Nephrologist approval required, slower titration |
Monthly initially |
| Stage 5 |
<15 or on dialysis |
Generally not recommended; specialist-only decision |
Specialist-directed |
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
The main risk is dehydration from side effects, which can temporarily affect kidney function or trigger acute kidney injury if not managed. Good monitoring catches this early.
What should I do if I become dehydrated from nausea?
Start with small, frequent sips of water throughout the day.
Signs that dehydration is becoming serious include producing much less urine than usual, dark urine, dizziness on standing, confusion, or unusual drowsiness.
If you can’t keep fluids down for more than 24 hours, or you notice these symptoms, 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 regularly review all your medications and adjust doses proactively rather than waiting for problems to arise.
Can I take Mounjaro if I’m on dialysis?
This requires a specialist nephrologist assessment. Some people on dialysis can use Mounjaro, but monitoring is complex, and not all providers are comfortable prescribing in this situation. 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 eat differently from 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 our programme provides.
People with CKD need coordination with nephrology services, more frequent kidney function tests, and specialist oversight for dose adjustments.
For people with CKD, management through NHS services or private providers with specialist kidney expertise is the safer route.
Can Mounjaro slow down CKD progression?
Evidence from the SURPASS-4 trial suggests that weight loss and improved blood sugar control from tirzepatide may help slow CKD progression in people with diabetic kidney disease.1
Mounjaro isn’t licensed specifically for kidney protection, so 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 needs 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.
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.
The main CKD-specific risk is dehydration from nausea and reduced appetite, which can trigger acute kidney injury. Good hydration and close monitoring help reduce this risk.
Nutrition requires more thought with CKD than for the general population. Protein, potassium, sodium, and hydration all need to be managed based on your individual blood results, ideally with guidance from a renal dietitian. Small, consistent movement habits support your kidney health, cardiovascular fitness, and muscle mass.
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.
Second Nature doesn’t currently accept people with CKD onto our medication programme, but 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.6
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
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- 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). Facts about kidneys.
- Electronic Medicines Compendium. (2026). Mounjaro KwikPen 2.5mg solution for injection in pre-filled pen – Summary of Product Characteristics.
- 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.
- NHS England. (2025). Weight management injections.
- 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.
