Is creatine a protein?

From the Guidelines

No, creatine is not a protein, as it is an organic compound composed of three amino acids (glycine, arginine, and methionine) but is not itself a protein 1.

Key Points

• Creatine is naturally produced in the body and found in some foods, primarily stored in muscle tissue, and plays a crucial role in energy production, particularly during high-intensity, short-duration activities.
• It helps regenerate adenosine triphosphate (ATP), the primary energy source for muscle contractions.
• While not a protein, creatine is often used as a dietary supplement, especially by athletes and bodybuilders, with the most common form being creatine monohydrate, typically taken in doses of 3-5 grams per day.
• According to the study published in Circulation in 2001 1, amino acids are the central units in protein metabolism, and creatine is converted from these amino acids, but it is not classified as a protein itself.

Clinical Considerations

• As with any supplement, it's advisable to consult with a healthcare professional before starting creatine use, especially for individuals with pre-existing medical conditions.
• The study highlights the importance of proper protein nutriture, which is based on proper balance and sufficient intake of essential amino acids and intake of an adequate amount of nitrogen for the body to produce nonessential amino acids 1.

From the Research

Definition of Creatine

• Creatine is a nitrogen-containing compound found in meat and fish 2
• It is a nonessential dietary component that can be synthesized in the body from three amino acids: arginine, glycine, and methionine 3
• Creatine is not a protein itself, but rather a substance that can be obtained through dietary sources or synthesized from amino acids

Biochemical Properties of Creatine

• Creatine administration increases creatine and phosphocreatine muscle concentration, allowing for an accelerated rate of ATP synthesis 4
• Creatine stimulates the creatine-creatine kinase-phosphocreatine circuit, which is related to the mitochondrial function as a highly organised system for the control of the subcellular adenylate pool 4
• Creatine entry into skeletal muscle is initially dependent on the extracellular concentration, but the creatine transport is subsequently downregulated 4

Dietary Sources of Creatine

• Creatine is available to adults via animal foodstuffs, principally skeletal muscle, or via supplements 3
• Vegans and infants fed on soy-based formulas receive no dietary creatine 3
• Human intake of creatine was probably much higher in Paleolithic times than today 3