Creatine is one of the most researched molecules in sports science. It plays a powerful role in cellular metabolism by enhancing energy generation in the body. While it is commonly used as a supplement to boost athletic performance, it's roles in disease prevention and mental health are only just beginning to be recognized.

Formula: C₄H₉N₃O₂
MW: 131.13 g/mol
Solubility: Slightly soluble in water
pH: Neutral
Precursors: Arginine, Glycine, Methionine
IUPAC Name: 2-(carbamimidoyl-methylamino)acetic acid
About half of the body's daily creatine requirement is produced endogenously, while the remainder is obtained through the diet, primarily from red meat and fish [4].

Energy Generation

The core function of creatine in the body is acting as a rapid energy buffer. It does this through its metabolised form: phosphocreatine (PCr).

When cells need energy fast — during intense exercise, for example — ATP (adenosine triphosphate) is consumed quickly. Phosphocreatine donates its phosphate group to ADP to regenerate ATP almost instantaneously, buying the cell time before slower metabolic pathways take over.

PCr + ADP + H⁺ ⟶ Creatine + ATP (catalysed by creatine kinase)

This reaction is reversible — during rest, excess ATP is used to convert creatine back into phosphocreatine, storing energy for the next burst of activity.

Where is it stored?

Approximately 95% of the body's creatine pool is stored in skeletal muscle, with the remaining 5% found in the brain, liver, and kidneys. Of the total creatine in muscle, roughly 60–70% exists as phosphocreatine at any given time [4].

Brain Function

The brain is an energetically exhausting organ — it accounts for roughly 20% of the body's total energy expenditure despite being only ~2% of body weight. Creatine plays a significant role in maintaining this energy supply, particularly in neurons during high cognitive demand.

Emerging research has linked creatine supplementation to improvements in mood and depressive symptoms. A 2012 study found that 5g/day of creatine monohydrate in combination with the antidepressant escitalopram significantly improved symptoms within 8 weeks in women with major depressive disorder, compared to those who did not take creatine [2].

put something here

Muscle Growth

talk about muscle hypertrophy specifically, link to fitness

Biochemistry — The Creatine Cycle

discuss the specifics of the biochemical reactions in cells

Beyond Muscle — Emerging Research

Recent research has revealed creatine's involvement in a surprisingly wide range of tissues and processes, including:

References