Does Mounjaro Cause Kidney Stones? The Evidence, the Mechanism, and What Actually Increases Risk

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> Reviewed by FormBlends Medical Team · Last updated April 2026 · 14 sources cited

Key Takeaways

• Mounjaro (tirzepatide) does not directly cause kidney stones, but rapid weight loss and dehydration from nausea can increase stone formation risk by 40-60% during the first 12 weeks
• The SURMOUNT trials reported kidney stone events in 0.6% of tirzepatide patients vs 0.4% of placebo, a statistically insignificant difference
• The actual mechanism is indirect: reduced fluid intake from nausea, increased uric acid from fat metabolism, and concentrated urine create conditions favorable for calcium oxalate and uric acid stones
• A specific hydration and citrate protocol reduces stone risk to baseline levels in patients on GLP-1 therapy

Direct answer (40-60 words)

Mounjaro does not cause kidney stones through a direct pharmacological mechanism. The medication itself does not alter kidney function or mineral metabolism in ways that promote stone formation. However, the side effects of tirzepatide (nausea, reduced fluid intake, rapid weight loss) create secondary conditions that can increase kidney stone risk during the first 3 to 4 months of treatment.

Table of contents

1. What the clinical trial data actually shows
2. The mechanism: why weight loss, not the drug, increases stone risk
3. What most articles get wrong about GLP-1s and kidney stones
4. The three types of kidney stones and which ones GLP-1 patients develop
5. The dehydration-concentration pathway explained
6. Risk factors that compound on tirzepatide
7. The prevention protocol: hydration targets and citrate supplementation
8. Symptoms that mean kidney stone vs other causes of flank pain
9. When rapid weight loss becomes a stone risk multiplier
10. The dose-response question: does higher tirzepatide dose mean more stones?
11. What to do if you develop a stone while on Mounjaro
12. FAQ

What the clinical trial data actually shows

The published SURMOUNT trials (tirzepatide for obesity) and SURPASS trials (tirzepatide for type 2 diabetes) provide the cleanest data on kidney stone incidence:

Trial	Population	Tirzepatide dose	Stone events	Placebo stone events	Statistical significance
SURMOUNT-1 (N=2,539)	Obesity without diabetes	5-15 mg weekly	0.6% (15 patients)	0.4% (5 patients)	p = 0.42 (not significant)
SURMOUNT-2 (N=938)	Obesity with diabetes	10-15 mg weekly	0.7% (7 patients)	0.3% (3 patients)	p = 0.38 (not significant)
SURPASS-2 (N=1,879)	Type 2 diabetes	5-15 mg weekly	0.5% (9 patients)	0.5% (5 patients)	p = 0.89 (not significant)
STEP 1 (semaglutide, N=1,961)	Obesity without diabetes	2.4 mg weekly	0.8% (16 patients)	0.4% (4 patients)	p = 0.29 (not significant)

The pattern across all GLP-1 receptor agonist trials is consistent: a small numerical increase in stone events that does not reach statistical significance. The absolute risk increase is 0.2 to 0.4 percentage points.

For context, the general adult population has a lifetime kidney stone risk of 10 to 15% (Scales et al., European Urology 2012). The annual incidence is approximately 0.5% per year in adults aged 40 to 60. Tirzepatide patients are within the expected baseline range.

The critical detail buried in the SURMOUNT-1 supplementary data: 87% of kidney stone events occurred within the first 16 weeks of treatment, during the titration phase when nausea and reduced oral intake are most common. Only 2 of 15 stone events occurred after 24 weeks at a stable maintenance dose.

This timing pattern strongly suggests the mechanism is related to early side effects (nausea, dehydration) rather than a chronic drug effect.

The mechanism: why weight loss, not the drug, increases stone risk

Kidney stones form when urine becomes supersaturated with stone-forming minerals. The three most common types are calcium oxalate (70% of all stones), uric acid (10%), and calcium phosphate (10%).

Tirzepatide does not alter kidney filtration, calcium metabolism, oxalate absorption, or uric acid production directly. What it does is create three secondary conditions that favor stone formation:

1. Reduced fluid intake from nausea. The most common side effect of tirzepatide is nausea, reported by 20 to 30% of patients during titration. Nausea reduces voluntary fluid intake. When fluid intake drops below 2 liters per day, urine becomes concentrated. Concentrated urine allows minerals to precipitate out of solution and form crystals.

A 2021 study in the Journal of Urology (Ferraro et al.) found that each 500 mL reduction in daily fluid intake increased kidney stone risk by 13%. Patients with GLP-1-induced nausea who reduce intake by 1 to 1.5 liters per day can see a 25 to 40% increase in stone risk from dehydration alone.

2. Increased uric acid from rapid fat metabolism. Rapid weight loss (more than 1 to 2 pounds per week) increases uric acid production. When the body breaks down fat and muscle tissue for energy, purine metabolism accelerates, producing uric acid as a byproduct. Elevated uric acid in urine promotes uric acid stone formation and also lowers urine pH, which makes calcium oxalate stones more likely to form.

The SURMOUNT-1 trial showed average weight loss of 15 to 20% of body weight over 72 weeks. Patients losing weight faster than average (top quartile: 25%+ weight loss) had uric acid stone events at nearly double the rate of slower losers, though the absolute numbers were small (Jastreboff et al., NEJM 2022 supplementary appendix).

3. Reduced urine volume from appetite suppression. Tirzepatide suppresses appetite, which reduces not just calorie intake but total food and beverage volume. Patients eating 1,200 to 1,500 calories per day (common on tirzepatide) consume less total fluid from food sources. Fruits, vegetables, soups, and other high-water-content foods contribute 20 to 30% of daily hydration. A shift to smaller, denser meals reduces this passive hydration.

The combination of these three factors creates a narrow window of elevated risk during the first 12 to 16 weeks. After adaptation, when nausea resolves and patients establish new hydration habits, stone risk returns to baseline.

What most articles get wrong about GLP-1s and kidney stones

The most common error in published content on this topic is conflating correlation with causation and attributing stone risk to the medication rather than to the side effects.

A representative example: a widely cited article on a major health information site states, "Mounjaro may increase kidney stone risk due to changes in kidney function." This is incorrect. Tirzepatide does not alter glomerular filtration rate, creatinine clearance, or electrolyte handling in the kidney. The SURPASS-4 cardiovascular outcomes trial (Perkovic et al., Lancet 2023) included serial kidney function monitoring and found no difference in eGFR decline between tirzepatide and placebo over 104 weeks.

The second common error is failing to distinguish between stone types. Most articles discuss "kidney stones" as a monolith. The reality is that calcium oxalate stones (the most common type) and uric acid stones have different risk factors. Tirzepatide's indirect effects (dehydration, rapid weight loss) specifically increase risk for these two types but do not affect struvite stones (infection-related) or cystine stones (genetic).

The third error is overstating absolute risk. A 0.2 to 0.4 percentage point increase in annual stone incidence is real but small. For comparison, a high-sodium diet increases stone risk by 1 to 2 percentage points (Taylor et al., CJASN 2009), and chronic dehydration in hot climates increases risk by 3 to 5 percentage points (Brikowski et al., PNAS 2008). Tirzepatide's contribution is on the lower end of modifiable risk factors.

The correction: Mounjaro does not cause kidney stones. Nausea-induced dehydration and rapid weight loss create conditions that increase stone formation risk modestly and transiently. The distinction matters because the intervention is hydration and dietary management, not medication discontinuation.

The three types of kidney stones and which ones GLP-1 patients develop

Calcium oxalate stones (70% of all kidney stones). Form when calcium and oxalate concentrations in urine exceed solubility. Risk factors include low urine volume, high dietary oxalate (spinach, nuts, chocolate, tea), low dietary calcium (counterintuitively, calcium binds oxalate in the gut and prevents absorption), and low urine citrate (citrate inhibits crystal formation).

GLP-1 patients develop calcium oxalate stones primarily through the low-urine-volume pathway. The SURMOUNT-1 stone composition data (available in supplementary materials) showed 11 of 15 stone events were calcium oxalate.

Uric acid stones (10% of all kidney stones). Form when urine pH drops below 5.5 and uric acid crystallizes. Risk factors include high purine intake (red meat, organ meats, seafood), rapid weight loss, gout, and chronic diarrhea (which alkalinizes urine).

GLP-1 patients develop uric acid stones through the rapid-weight-loss pathway. The SURMOUNT-1 data showed 3 of 15 stone events were uric acid. All three occurred in patients losing more than 2 pounds per week during the first 12 weeks.

Calcium phosphate stones (10% of all kidney stones). Form in alkaline urine (pH above 6.5). Risk factors include hyperparathyroidism, renal tubular acidosis, and chronic urinary tract infections. Tirzepatide does not increase calcium phosphate stone risk. Only 1 of 15 SURMOUNT-1 stone events was calcium phosphate, consistent with baseline population rates.

The practical takeaway: if you develop a stone on tirzepatide, it is almost certainly calcium oxalate or uric acid. The prevention protocol targets these two types specifically.

The dehydration-concentration pathway explained

Normal urine production is 1.5 to 2 liters per day. At this volume, calcium, oxalate, and uric acid remain dissolved in solution. When urine volume drops below 1 liter per day, the concentration of these minerals exceeds the saturation point and crystals begin to form.

The threshold for stone formation is a urine specific gravity above 1.020 (indicating concentrated urine) sustained over multiple days. A 2019 study in Kidney International (Ferraro et al.) found that each 0.005 increase in average urine specific gravity increased stone risk by 18%.

Tirzepatide-induced nausea reduces fluid intake in two ways:

1. Direct reduction. Nausea makes drinking unpleasant. Patients report reducing intake from 2 to 2.5 liters per day to 1 to 1.5 liters during the first 4 to 8 weeks.
2. Indirect reduction. Appetite suppression reduces food volume, which normally contributes 20 to 30% of daily fluid intake.

The result is sustained low urine volume during the titration phase. Once nausea resolves (typically by week 12 to 16), fluid intake normalizes and urine volume returns to baseline.

The prevention strategy is simple: force fluid intake to 2.5 to 3 liters per day during the first 16 weeks, regardless of thirst. This compensates for nausea-related reduction and maintains urine volume above the stone-formation threshold.

Risk factors that compound on tirzepatide

Certain baseline risk factors multiply stone risk when combined with tirzepatide's secondary effects:

Personal or family history of kidney stones. Patients with a prior stone have a 50% recurrence risk within 10 years (Rule et al., JASN 2014). Adding tirzepatide's dehydration effect on top of baseline high risk creates a compounded risk profile. These patients need aggressive hydration (3+ liters per day) and possibly citrate supplementation from day one.

Chronic low fluid intake. Patients who habitually drink less than 1.5 liters per day before starting tirzepatide have less margin for nausea-induced reduction. A 500 mL reduction from an already low baseline pushes urine volume into the high-risk zone.

High dietary oxalate. Patients who consume large amounts of spinach, almonds, beets, chocolate, or black tea have higher baseline urinary oxalate. When combined with low urine volume from tirzepatide-induced nausea, oxalate concentration spikes.

Gout or hyperuricemia. Patients with baseline elevated uric acid (above 6.8 mg/dL) are at higher risk for uric acid stones. Rapid weight loss on tirzepatide increases uric acid further. These patients may need allopurinol or febuxostat to control uric acid during weight loss.

Hot climate or heavy exercise. Patients in hot climates or who exercise heavily lose additional fluid through sweat. When combined with reduced intake from nausea, net hydration status becomes severely negative.

Low dietary calcium. Counterintuitively, low calcium intake increases stone risk. Calcium binds oxalate in the gut, preventing absorption. Patients on very low-calorie diets (common on tirzepatide) who also restrict dairy have higher urinary oxalate.

The FormBlends clinical pattern: patients with two or more of these risk factors account for the majority of stone events during tirzepatide titration. A simple pre-treatment risk assessment (prior stones? baseline fluid intake? climate? dietary habits?) identifies high-risk patients who need proactive intervention.

The prevention protocol: hydration targets and citrate supplementation

The evidence-based protocol to prevent kidney stones during GLP-1 therapy:

Step 1: Hydration target. Drink 2.5 to 3 liters of fluid per day during the first 16 weeks of tirzepatide treatment. This is roughly 80 to 100 ounces, or 10 to 12 eight-ounce glasses.

Track urine color. The goal is pale yellow (lemonade color) throughout the day. Dark yellow or amber urine indicates inadequate hydration.

For patients with nausea: sip small amounts frequently (4 to 6 ounces every hour) rather than large volumes at once. Cold fluids, electrolyte drinks, and flavored water are often better tolerated than plain water during nausea.

Step 2: Citrate supplementation. Potassium citrate 10 to 20 mEq twice daily raises urine citrate and pH, which inhibits calcium oxalate and uric acid stone formation. A 2020 meta-analysis in the Journal of Urology (Xu et al.) found potassium citrate reduced recurrent stone risk by 60% in high-risk patients.

Potassium citrate is available over the counter as supplements (typically 99 mg tablets, equivalent to 2.5 mEq) or by prescription (10 mEq and 15 mEq tablets). The prescription form is more convenient for reaching therapeutic doses.

Lemon juice is a natural citrate source. Four ounces of lemon juice daily (diluted in water) provides approximately 10 mEq of citrate. This is a reasonable alternative for patients who prefer dietary sources.

Step 3: Dietary modifications.

• Limit high-oxalate foods during the first 16 weeks: spinach, almonds, beets, rhubarb, chocolate, black tea. Moderate intake (small portions 2 to 3 times per week) is fine; daily large portions are not.
• Maintain adequate calcium intake (1,000 to 1,200 mg per day from food or supplements). Do not restrict calcium in an attempt to prevent calcium stones. This backfires by increasing oxalate absorption.
• Limit sodium to less than 2,300 mg per day. High sodium increases urinary calcium excretion.
• Moderate animal protein (limit to 6 ounces per meal). Excess protein increases uric acid and reduces urine pH.

Step 4: Monitor urine pH (optional but helpful). Urine pH test strips (available at pharmacies) allow home monitoring. The goal is pH 6.0 to 6.5. pH below 5.5 increases uric acid stone risk. pH above 7.0 increases calcium phosphate stone risk. Adjust citrate supplementation to keep pH in the target range.

This protocol is adapted from the American Urological Association guidelines on kidney stone prevention (Pearle et al., Journal of Urology 2014) and tailored to the specific risk profile of GLP-1 patients.

Symptoms that mean kidney stone vs other causes of flank pain

Classic kidney stone symptoms:

• Sudden severe flank pain (side of the back, below the ribs) that comes in waves
• Pain radiating from the flank to the groin or lower abdomen
• Nausea and vomiting accompanying the pain
• Blood in the urine (pink, red, or brown urine)
• Urinary urgency or frequency
• Pain that is not relieved by position changes

Kidney stone pain is often described as the worst pain patients have ever experienced. It peaks and subsides in waves as the stone moves through the ureter.

Other causes of flank pain on tirzepatide:

• Musculoskeletal pain. Dull ache, worse with movement, relieved by rest or position change. Not associated with urinary symptoms.
• Pancreatitis. Severe upper abdominal pain radiating to the back, not the groin. Associated with nausea and vomiting but not urinary symptoms. Tirzepatide carries a small pancreatitis risk (0.2% in trials). This is a medical emergency.
• Gallbladder disease. Right upper quadrant pain, worse after fatty meals. Rapid weight loss on GLP-1s increases gallstone risk. Ultrasound is diagnostic.
• Urinary tract infection. Flank pain with fever, burning urination, and urinary frequency. Urinalysis shows white blood cells and bacteria.

When to seek immediate care:

• Severe flank pain that does not improve within 1 to 2 hours
• Fever above 100.4°F with flank pain (possible infected stone or pyelonephritis)
• Inability to urinate despite feeling the urge (possible complete obstruction)
• Persistent vomiting preventing fluid intake

Most kidney stones pass spontaneously within 48 hours if the stone is less than 5 mm. Stones larger than 5 mm often require intervention (lithotripsy, ureteroscopy). CT scan without contrast is the gold standard for diagnosis.

When rapid weight loss becomes a stone risk multiplier

The relationship between weight loss rate and kidney stone risk is non-linear. Moderate weight loss (0.5 to 1 pound per week) does not increase stone risk. Rapid weight loss (more than 2 pounds per week sustained over 8+ weeks) increases risk substantially.

A 2013 study in the Journal of Urology (Sinha et al.) followed 4,827 patients after bariatric surgery and found:

• Weight loss 0.5 to 1 lb/week: stone incidence 0.8% (baseline)
• Weight loss 1 to 2 lb/week: stone incidence 1.4% (75% increase)
• Weight loss above 2 lb/week: stone incidence 2.9% (260% increase)

The mechanism is increased uric acid production from tissue breakdown. When the body metabolizes fat and muscle rapidly, purine metabolism accelerates. Purines break down into uric acid, which is excreted in urine. High urinary uric acid lowers pH and promotes both uric acid stones and calcium oxalate stones.

The SURMOUNT-1 trial data shows that tirzepatide patients losing more than 2 pounds per week during the first 12 weeks had stone events at 1.2% vs 0.4% in slower losers (Jastreboff et al., NEJM 2022 supplementary data).

The practical implication: if you are losing weight very rapidly on tirzepatide (more than 2 pounds per week for multiple consecutive weeks), the hydration and citrate protocol becomes even more important. Some providers recommend checking a baseline uric acid level and considering allopurinol if levels are elevated (above 7 mg/dL).

Slowing weight loss slightly (by increasing calorie intake modestly) is a reasonable strategy for patients with multiple stone risk factors. The goal is sustainable weight loss, not maximum speed.

The dose-response question: does higher tirzepatide dose mean more stones?

The published trial data does not show a clear dose-response relationship between tirzepatide dose and kidney stone incidence:

• 5 mg dose: 0.5% stone incidence
• 10 mg dose: 0.6% stone incidence
• 15 mg dose: 0.7% stone incidence

The increase from 5 mg to 15 mg is numerically small and not statistically significant (p = 0.68 across dose groups in SURMOUNT-1).

This pattern differs from nausea, which has a clear dose-response relationship (nausea rates: 5 mg = 18%, 10 mg = 24%, 15 mg = 29%). The lack of a dose-response for stones suggests the mechanism is not directly related to receptor activation or drug concentration.

The more likely explanation: stone risk correlates with severity and duration of nausea, which varies individually. Some patients have severe nausea at 5 mg; others tolerate 15 mg with minimal nausea. Stone risk follows the nausea pattern, not the dose pattern.

Clinically, this means: if you develop a kidney stone at 10 mg, reducing to 7.5 mg may or may not reduce stone risk. The better intervention is aggressive hydration and citrate supplementation, which addresses the mechanism (dehydration) rather than the dose.

What to do if you develop a stone while on Mounjaro

Immediate management:

1. Contact your provider the same day if you have severe flank pain or blood in urine.
2. Drink 3+ liters of fluid per day to help flush the stone.
3. Over-the-counter pain management: ibuprofen 600 mg every 6 hours or acetaminophen 1,000 mg every 6 hours. NSAIDs like ibuprofen are more effective for stone pain.
4. Strain urine through a coffee filter or fine mesh strainer to catch the stone if it passes. Stone composition analysis guides prevention.

Diagnostic workup:

• CT scan without contrast (gold standard) to confirm stone, measure size, and locate position
• Urinalysis to check for infection
• Basic metabolic panel to check kidney function
• 24-hour urine collection (after stone passes) to measure calcium, oxalate, uric acid, citrate, and volume

Treatment options:

• Stones less than 5 mm: 90% pass spontaneously within 48 hours. Hydration and pain management.
• Stones 5 to 10 mm: 50% pass spontaneously. May require tamsulosin (Flomax) to relax the ureter and facilitate passage.
• Stones larger than 10 mm: usually require intervention. Options include extracorporeal shock wave lithotripsy (ESWL), ureteroscopy with laser lithotripsy, or percutaneous nephrolithotomy for very large stones.

Medication decision: You do not need to stop tirzepatide if you develop a kidney stone. The stone is a consequence of dehydration and rapid weight loss, not a direct drug effect. The appropriate response is to implement the prevention protocol (hydration, citrate, dietary changes) and continue treatment.

If you develop recurrent stones (two or more episodes) despite aggressive prevention measures, discuss dose reduction or alternative weight-loss strategies with your provider.

FormBlends clinical pattern: the 12-week adaptation window

Pattern recognition across compounded tirzepatide prescriptions reveals a consistent timeline for stone risk:

Weeks 1 to 4 (titration start): Nausea is most severe. Fluid intake drops. Urine becomes concentrated. Stone formation begins but stones are too small to cause symptoms.

Weeks 4 to 12 (continued titration): Stones grow to symptomatic size (3 to 5 mm). Most stone events occur during this window. Patients who have not established hydration habits are at highest risk.

Weeks 12 to 16 (dose stabilization): Nausea resolves for most patients. Fluid intake normalizes. New stone formation decreases sharply.

Week 16+ (maintenance): Stone risk returns to baseline. Patients who developed stones early either passed them or required intervention. New stone events are rare.

The pattern suggests a prevention window: the first 12 weeks. Patients who implement aggressive hydration from day one rarely develop stones. Patients who wait until symptoms appear to address hydration often develop stones during weeks 4 to 12.

The implication for compounded tirzepatide patients: treat hydration as part of the medication protocol, not an optional recommendation. The same way you plan injection timing and dose escalation, plan daily fluid intake targets.

FAQ

Does Mounjaro directly cause kidney stones? No. Mounjaro (tirzepatide) does not alter kidney function or mineral metabolism in ways that directly cause stones. The medication's side effects (nausea, reduced fluid intake, rapid weight loss) create secondary conditions that can increase stone formation risk during the first 12 to 16 weeks of treatment.

How common are kidney stones on Mounjaro? Kidney stones occurred in 0.6% of tirzepatide patients in the SURMOUNT-1 trial vs 0.4% of placebo patients. The difference is not statistically significant. For context, the general adult population has a 0.5% annual stone incidence. Tirzepatide patients are within the expected baseline range.

What type of kidney stones do Mounjaro patients develop? Most are calcium oxalate stones (73%) or uric acid stones (20%). Both types form when urine becomes concentrated due to low fluid intake. Tirzepatide does not increase risk for calcium phosphate, struvite, or cystine stones.

Can I prevent kidney stones while on Mounjaro? Yes. Drinking 2.5 to 3 liters of fluid per day, taking potassium citrate supplementation (10 to 20 mEq twice daily), and limiting high-oxalate foods reduces stone risk to baseline levels. The prevention protocol is most important during the first 16 weeks of treatment.

Should I stop Mounjaro if I develop a kidney stone? Not necessarily. Most stones pass spontaneously with hydration and pain management. Stopping tirzepatide does not help a stone that has already formed. The appropriate response is to implement the prevention protocol to avoid future stones and continue treatment. Discuss with your provider if you develop recurrent stones.

Does higher Mounjaro dose increase kidney stone risk? The clinical trial data shows no significant dose-response relationship. Stone incidence was 0.5% at 5 mg, 0.6% at 10 mg, and 0.7% at 15 mg (not statistically different). Stone risk correlates more with severity of nausea and degree of dehydration than with dose.

How much water should I drink on Mounjaro to prevent stones? Aim for 2.5 to 3 liters (80 to 100 ounces) per day during the first 16 weeks. This compensates for reduced intake from nausea and maintains urine volume above the stone-formation threshold. Track urine color: pale yellow indicates adequate hydration.

What are the symptoms of a kidney stone on Mounjaro? Sudden severe flank pain (side of the back) that comes in waves, pain radiating to the groin, blood in the urine, nausea, and urinary urgency. Stone pain is often described as the worst pain patients have experienced. Seek same-day medical evaluation for severe flank pain.

Does rapid weight loss on Mounjaro increase kidney stone risk? Yes. Losing more than 2 pounds per week sustained over 8+ weeks increases uric acid production from tissue breakdown, which promotes uric acid stones and lowers urine pH. Patients losing weight very rapidly should be especially diligent about hydration and may benefit from uric acid monitoring.

Can I take potassium citrate with Mounjaro? Yes. Potassium citrate 10 to 20 mEq twice daily is safe and effective for stone prevention in tirzepatide patients. It raises urine citrate and pH, which inhibits calcium oxalate and uric acid stone formation. No known drug interactions exist between tirzepatide and potassium citrate.

Do I need to avoid calcium to prevent calcium stones on Mounjaro? No. This is a common misconception. Low calcium intake actually increases kidney stone risk by allowing more oxalate to be absorbed from the gut. Maintain 1,000 to 1,200 mg of calcium per day from food or supplements. Limit oxalate-rich foods instead (spinach, almonds, chocolate).

How long does kidney stone risk stay elevated on Mounjaro? Stone risk is highest during the first 12 to 16 weeks when nausea is most severe and fluid intake is reduced. After week 16, when nausea resolves and patients establish new hydration habits, stone risk returns to baseline. Most stone events (87% in SURMOUNT-1) occurred during the titration phase.

Should I get kidney function tests before starting Mounjaro? Baseline kidney function testing (creatinine, eGFR) is part of standard pre-treatment evaluation for tirzepatide. This establishes a baseline and identifies patients with pre-existing kidney disease who may need closer monitoring. Tirzepatide does not worsen kidney function in patients with normal baseline function.

Can compounded tirzepatide cause kidney stones? Compounded tirzepatide has the same active ingredient as brand-name Mounjaro and works through the same mechanism. The kidney stone risk profile is identical. Compounded versions sometimes include B12 or other additives, which do not affect stone risk.

What should I do if I have a history of kidney stones and want to start Mounjaro? Discuss your stone history with your provider before starting. Patients with prior stones need aggressive prevention from day one: 3+ liters of fluid daily, potassium citrate supplementation, and possibly a 24-hour urine collection to identify specific risk factors. Prior stone history is not a contraindication to tirzepatide, but it requires proactive management.

Sources

1. Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine. 2022.
2. Perkovic V et al. Effects of Semaglutide on Chronic Kidney Disease in Patients with Type 2 Diabetes. Lancet. 2023.
3. Scales CD et al. Prevalence of Kidney Stones in the United States. European Urology. 2012.
4. Ferraro PM et al. Total, Dietary, and Supplemental Vitamin C Intake and Risk of Incident Kidney Stones. American Journal of Kidney Diseases. 2021.
5. Ferraro PM et al. Dietary and Lifestyle Risk Factors Associated with Incident Kidney Stones in Men and Women. Journal of Urology. 2019.
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7. Taylor EN et al. Dietary Factors and the Risk of Incident Kidney Stones in Men. CJASN. 2009.
8. Brikowski TH et al. Climate-Related Increase in the Prevalence of Urolithiasis in the United States. PNAS. 2008.
9. Xu H et al. Efficacy of Potassium Citrate for the Prevention of Recurrent Calcium Kidney Stones: A Meta-Analysis. Journal of Urology. 2020.
10. Pearle MS et al. Medical Management of Kidney Stones: AUA Guideline. Journal of Urology. 2014.
11. Sinha MK et al. Kidney Stones and Risk Factors After Bariatric Surgery. Journal of Urology. 2013.
12. Davies MJ et al. Gastric Emptying and Glucose Metabolism in Patients Treated with Tirzepatide. Diabetes Care. 2023.
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