Creatinine

Creatinine is a kidney-related biomarker, commonly abbreviated as Cr. It is used as a marker in kidney-focused health assessment.

Creatinine is tested from a serum sample. Fasting is not required for this measurement, so the test can generally be arranged without fasting beforehand.

When reviewing the result, use the reference information provided with the report. The page distinguishes a general reference range from an optimal range and also shows sex-specific ranges, so interpretation should account for which interval applies rather than relying on a single universal cutoff.

Creatinine may also be reviewed alongside Egfr, Bun, and Cystatin C when a broader assessment is needed. A clinician can help interpret the result in the context of the relevant range and the reason the test was ordered.

Creatinine is reported from a serum sample in mg/dL. Fasting is not required for this measurement.

The reference range is 0.6–1.2 mg/dL. The tighter optimal range is 0.7–1.0 mg/dL, so the optimal range sits within the broader reference range. Sex-specific ranges are also shown: 0.7–1.3 mg/dL for males and 0.6–1.1 mg/dL for females.

Read any result against the range printed on the same laboratory report, including its units and the applicable range. A single creatinine value is not a diagnosis, and an out-of-range result should be discussed with a clinician. The result should be considered in the context of the report and the person’s clinical circumstances rather than interpreted in isolation.

Creatinine was measured directly in trials of several interventions, with results in both directions. Decreases were reported with Resveratrol, Astragalus, Reishi, Sodium Bicarbonate, Quercetin, Vitamin E, Cordyceps, Ginkgo Biloba, Berberine, Melatonin, and Coenzyme Q10. Creatine increased creatinine. Milk Thistle (Silymarin), Saffron Extract, and Curcumin were unchanged in the measured results.

These findings describe movement in the marker, not whether a change is desirable for a particular person. Because the optimal direction is a range rather than simply lower or higher, interpretation depends on where the result sits relative to that range and on the clinical context. The interventions also differ in study design and consistency, so a reported direction should not be treated as a uniform effect across all settings.

Across the interventions, creatinine was typically rechecked between 0.9 and 37.0 weeks after the relevant intervention or study period. The timing and setting varied, including peri-procedural assessment for Sodium Bicarbonate. Any interpretation in the context of a medical condition is best discussed with a clinician.