Does creatine supplementation cause kidney disease with an eGFR of 37?

Creatine Supplementation and Apparent Kidney Disease

This is almost certainly NOT kidney disease—creatine supplementation artificially elevates serum creatinine without affecting actual kidney function, creating a false appearance of renal impairment that will resolve after stopping the supplement. 1, 2, 3

Why This Appears to Be False Kidney Disease

Creatine's Effect on Creatinine Measurements

• Creatine supplements directly increase serum creatinine levels because creatine is spontaneously converted to creatinine in the body, independent of actual kidney function 2, 4, 5
• Your timing is critical: taking creatine just 2 days before bloodwork will significantly elevate serum creatinine, falsely lowering the calculated eGFR 1, 2
• The eGFR calculation (MDRD or CKD-EPI equations) relies heavily on serum creatinine and assumes it reflects kidney filtration capacity—but with exogenous creatine supplementation, this assumption breaks down completely 1, 2

Your Specific Lab Pattern Suggests Supplement Effect

• Your BUN/Creatinine ratio of 8 is abnormally low (normal is 10-20), which is the opposite pattern seen in true kidney disease 6, 7
• In actual kidney disease, both BUN and creatinine rise together or BUN rises disproportionately higher 6, 7
• Your pattern—elevated creatinine with normal-to-low BUN—is classic for creatine supplementation combined with strength training (high muscle turnover) 2, 4

Evidence That Creatine Does NOT Cause Kidney Disease

Clinical Trial Data

• Controlled clinical trials consistently show creatine supplementation does not impair kidney function when measured by reliable methods (not just serum creatinine) 5
• A prospective study of a young man with a single kidney and baseline eGFR of 82 mL/min showed that 35 days of high-dose creatine (20g/day for 5 days, then 5g/day for 30 days) did not change actual GFR measured by chromium-51 EDTA clearance (gold standard), despite serum creatinine rising from 1.03 to 1.27 mg/dL 3
• The same study showed proteinuria remained stable and albuminuria actually decreased, confirming no kidney damage occurred 3

Safety Profile

• Multiple systematic reviews conclude that creatine supplements are safe and do not cause renal disease in healthy individuals 4, 5
• Case reports suggesting kidney damage from creatine are extremely rare and typically involve confounding factors 5

What You Must Do Next

Immediate Action

1. Stop creatine supplementation immediately and wait 6-8 weeks before retesting 1, 2
2. Do NOT start any kidney disease treatments based on these labs alone 1

Proper Kidney Function Assessment

After stopping creatine for 6-8 weeks, obtain:

• Repeat serum creatinine and eGFR to see if values normalize 1, 2
• Spot urine albumin-to-creatinine ratio (UACR) to assess for actual kidney damage—this is the preferred method and should be <30 mg/g creatinine if kidneys are healthy 8, 6
• If UACR is normal and creatinine normalizes after stopping creatine, you never had kidney disease 6, 7

Additional Considerations

• High protein intake (common with strength training) can also elevate BUN, further confusing the picture when combined with creatine 4
• Your muscle mass from strength training naturally produces more creatinine than average, which can push you toward the upper end of normal even without supplements 6, 2

When to Actually Worry About Kidney Disease

True chronic kidney disease requires BOTH 8:

1. eGFR <60 mL/min/1.73 m² on repeat testing (not just once, and not while on creatine)
2. Evidence of kidney damage such as:
   • Albuminuria (UACR ≥30 mg/g creatinine) 8
   • Abnormal kidney imaging 8
   • Hematuria or abnormal urinary sediment 6, 7

Critical Pitfall to Avoid

The most common error is diagnosing chronic kidney disease based solely on a single elevated creatinine or low eGFR without considering exogenous creatine intake. 1, 2 This leads to unnecessary nephrology referrals, patient anxiety, and potential insurance/employment consequences for a completely reversible laboratory artifact 1.

Future Creatine Use

• If kidney function normalizes after stopping creatine, you can safely resume supplementation if desired—creatine does not cause kidney disease in healthy individuals 3, 5
• However, be aware that it will continue to artificially elevate serum creatinine, so always disclose supplement use before bloodwork and consider stopping it 6-8 weeks before any kidney function testing 1, 2