Comparison of new forms of creatine in raising plasma creatine levels.
Level 2 - randomized trial
Individual randomized balanced crossover trial
PubMed 17997838 · doi:10.1186/1550-2783-4-17
What was done
Six healthy subjects (three male, three female) ingested a single dose containing an isomolar amount of creatine (4.4 g) administered as creatine monohydrate (CrM), tri-creatine citrate (CrC), or creatine pyruvate (CrPyr) in a balanced crossover design. Plasma creatine concentrations were tracked over eight hours post-ingestion to evaluate pharmacokinetic parameters using repeated measures ANOVA.
What was found
CrPyr ingestion resulted in significantly higher mean peak plasma concentrations (17% higher) and area under the curve (AUC, 14% higher) compared to CrM and CrC. Peak concentration and AUC did not differ significantly between CrM and CrC. Estimated velocity constants for absorption (ka) and elimination (kel) were not significantly different among the three forms. Ingestion of CrPyr did not alter plasma pyruvate concentrations.
Why it matters
This study compares the acute absorption kinetics of novel creatine salts against standard creatine monohydrate, demonstrating modest differences in plasma concentrations that the authors suggest are unlikely to alter long-term muscle creatine accumulation.
Limits
The sample size is extremely small (n = 6), limiting statistical power and generalizability. Intramuscular creatine concentrations were not measured, so plasma pharmacokinetic differences cannot be directly linked to muscle retention or functional performance. Blood sampling frequency during the early absorption phase was limited.
Cited by
- supports The bioavailability of creatine monohydrate is nearly 100%.