creatinine

American  

[kree-at-n-een, -in] / kriˈæt nˌin, -ɪn /

noun

Biochemistry.

1. a crystalline end product of creatine metabolism, C 4 H 7 N 3 O, occurring in urine, muscle, and blood.

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creatinine British  

/ kriːˈætəˌniːn /

noun

1. an anhydride of creatine that is abundant in muscle and excreted in the urine

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creatinine Scientific  

/ krē-ăt′n-ēn′,-ĭn /

1. A compound formed by the metabolism of creatine, found in muscle tissue and blood and normally excreted in the urine as a metabolic waste. Measurement of creatinine levels in the blood is used to evaluate kidney function. Chemical formula: C ₄ H ₇ N ₃ O.

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Etymology

Origin of creatinine

First recorded in 1850–55; from German Kreatinin, equivalent to kreatin creatine ( def. ) + -in -ine ² ( def. )

Compare meaning

How does creatinine compare to similar and commonly confused words? Explore the most common comparisons:

• creatine vs. creatinine

Example Sentences

Dr. Mehdi Boroujerdi, a pharmaceutical researcher and former professor, has conducted an in depth review of creatine in the Handbook of Creatine and Creatinine In Vivo Kinetics.

From Science Daily • May 4, 2026

Creatinine is produced from creatine with great facility; it exists in urine.

From The Chemistry of Food and Nutrition by Duncan, A. W.