Study Overview
Persky and Brazeau (2001) published a thorough pharmacological review of creatine monohydrate in Clinical Pharmacology and Therapeutics.
This review treated creatine as a pharmaceutical agent, systematically examining its pharmacokinetics (absorption, distribution, metabolism, and excretion), pharmacodynamics (mechanism of action), drug interactions, and clinical applications.
This approach provided a rigorous pharmacological framework for understanding creatine supplementation (Kreider et al., 2017) .
Key Findings
- Near-complete oral bioavailability: Creatine monohydrate in solution is almost completely absorbed from the gastrointestinal tract, with peak plasma levels occurring 1-2 hours post-ingestion
- Sodium-dependent transport: Creatine enters cells primarily through a specific sodium- and chloride-dependent creatine transporter (CrT/SLC6A8). This transporter is saturable, which explains why excessive single doses provide diminishing returns
- Muscle is the primary storage site: Approximately 95% of body creatine resides in skeletal muscle, with total stores of 120-140g in a typical 70 kg adult
- Constant turnover: Approximately 1.7% of the body’s creatine pool is converted to creatinine daily (about 2g/day), requiring constant replenishment through diet and endogenous synthesis
- Saturation kinetics: Muscle creatine stores have an upper limit. Once saturated (typically 150-160 mmol/kg dry weight), additional creatine intake is excreted rather than stored
- Co-ingestion with carbohydrates: The review noted that taking creatine with carbohydrates enhances insulin-mediated creatine uptake into muscle cells
Practical Implications
This pharmacological perspective provides important practical guidance for creatine users.
Understanding that creatine transport is saturable explains why spreading doses throughout the day (or using smaller maintenance doses) is more efficient than taking large single doses.
The finding that carbohydrate co-ingestion improves creatine uptake supports the practical recommendation to take creatine with meals — Malaysian meals typically include rice or other carbohydrates, making meal-time dosing convenient and effective.
Understanding the daily turnover rate (~2g/day) also explains why 3-5g/day is the recommended maintenance dose — it replaces what is lost and gradually maximises muscle stores over 3-4 weeks without the need for a loading phase (Harris et al., 1992) .
For Malaysian consumers, this pharmacological knowledge helps make informed decisions: choose creatine monohydrate (best studied form with near-complete bioavailability), take it with meals, use 3-5g/day consistently, and understand that individual response varies based on baseline stores and transporter expression.
Study Limitations
- As a review article, it synthesised existing data rather than generating new experimental findings
- Some pharmacokinetic parameters were derived from relatively small studies
- The review focused primarily on creatine monohydrate — pharmacokinetics of alternative creatine forms were not extensively covered
- Individual variation in creatine transporter expression was acknowledged but not fully characterised
- Long-term pharmacokinetic adaptations (changes in transporter expression with chronic use) were not well understood at the time
Where This Fits in the Evidence
Persky and Brazeau (2001) is the pharmacological backbone underneath much of the practical advice on creatine. By treating monohydrate as a drug and tracing its absorption, distribution, turnover and saturable transport, the review explains why the familiar dosing rules work — near-complete bioavailability, a saturable transporter that punishes oversized single doses, and a steady daily loss of roughly 2g that 3-5g a day comfortably replaces. As a synthesis of earlier data it generates no new experiments of its own, which is precisely why it pairs well with the position-stand recommendations in the ISSN position stand. The broader evidence base is collected in our research library.
Sources & References
This page summarises Persky AM, Brazeau GA. Clinical pharmacology of the dietary supplement creatine monohydrate. Pharmacological Reviews.
2001;53(2):161-176.