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Creatinine

Kidney Unit: mg/dL

Primary kidney filtration marker

Also known as: Cr,Serum Creatinine

Reference Ranges

Clinical Reference 0.6 – 1.2 mg/dL
Optimal Range 0.7 – 1.0 mg/dL
Critical Range > 7.0 mg/dL

Varies by muscle mass and sex

Related Conditions

Kidney Disease High

Food & Lifestyle Recommendations

🍎 Food Avoid excessive red meat and creatine supplements before blood tests; stay hydrated Dietary creatine and cooked meat can temporarily raise creatinine
🍎 Food Avoid high-dose creatine supplements which can raise creatinine Creatine supplementation increases serum creatinine without necessarily reducing kidney function
🍎 Food Stay well-hydrated with water — aim for clear or light yellow urine Adequate hydration supports kidney clearance and may reduce creatinine concentration
🏃 Exercise Avoid very intense exercise before blood tests — it can temporarily raise creatinine Muscle breakdown from intense exercise releases creatinine into blood

Evidence-Backed Supplements

When High

  • Nac Tier A May Decrease

    Moderate evidence; NAC may improve renal function markers. Some trials show creatinine reduction in contrast-induced nephropathy prevention.

    N-Acetyl Cysteine 600–1200 mg/day Morning or divided doses
    PMID 30746681 PMID 39349461 PMID 33294991
  • Omega 3 Tier A May Decrease

    Limited evidence; omega-3 may slow CKD progression. Meta-analyses show modest benefit on renal function markers.

    Fish oil (EPA+DHA) 1000–2000 mg EPA+DHA/day With meals
    PMID 30019766 PMID 32114706 PMID 30480773
  • Probiotics Tier A May Decrease

    Limited evidence; certain probiotic strains may reduce creatinine by metabolizing uremic toxins in the gut.

    Multi-strain probiotic (Lactobacillus + Bifidobacterium) 5–50 billion CFU/day Morning on empty stomach
    PMID 36001877 PMID 25927096 PMID 32128794
  • Astragalus Tier A May Support Renal Function TCM

    Astragalus membranaceus shows modest creatinine reduction in some CKD studies; evidence limited

    PMID 25335553 PMID 27905672 PMID 38351506

Questions to Ask Your Doctor

  • Should my creatinine be interpreted differently based on my muscle mass? High muscle mass = higher baseline creatinine
  • How concerned should I be about my elevated creatinine, and what follow-up tests do I need? Elevated creatinine may indicate reduced kidney function. eGFR calculation and further kidney workup are recommended.

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