Creatine ethyl ester rapidly degrades to creatinine in stomach acid
Child R1 and Tallon MJ2
1Department of Life Sciences, Kingston University, Penrhyn Rd, Kingston-upon-Thames, United Kingdom. 2University of Northumbria, Sport Sciences, Northumbria University, Northumberland Building, Newcastle upon Tyne, United Kingdom, DrChild@CR-Technologies.net
Creatine ethyl ester (CEE) is a commercially available synthetic creatine that is now widely used in dietary supplements. It comprises of creatine with an ethyl group attached and this molecular configuration is reported to provide several advantages over creatine monohydrate (CM). The Medical Research Institute (CA, USA) claim that the CEE in their product (CE2) provides greater solubility in lipids, leading to improved absorption. Similarly San (San Corporation, CA, USA) claim that the CEE in their product (San CM2 Alpha) avoids the breakdown of creatine to creatinine in stomach acids. Ultimately it is claimed that CEE products provide greater absorption and efficacy than CM. To date, none of these claims have been evaluated by an independent, or university laboratory and no comparative data are available on CEE and CM.
This study assessed the availability of creatine from three commercial creatine products during degradation in acidic conditions similar to those that occur in the stomach. They comprised of two products containing CEE (San CM2 Alpha and CE2) and commercially available CM (Creapure?). An independent laboratory, using testing guidelines recommended by the United States Pharmacopeia (USP), performed the analysis. Each product was incubated in 900ml of pH 1 HCL at 37? 1oC and samples where drawn at 5, 30 and 120 minutes. Creatine availability was assessed by immediately assaying for free creatine, CEE and the creatine breakdown product creatinine, using HPLC (UV)
After 30 minutes incubation only 73% of the initial CEE present was available from CE2, while the amount of CEE available from San CM2 Alpha was even lower at only 62%. In contrast, more than 99% of the creatine remained available from the CM product. These reductions in CEE availability were accompanied by substantial creatinine formation, without the appearance of free creatine. After 120minutes incubation 72% of the CEE was available from CE2 with only 11% available from San CM2 Alpha, while more than 99% of the creatine remained available from CM.
CEE is claimed to provide several advantages over CM because of increased solubility and stability. In practice, the addition of the ethyl group to creatine actually reduces acid stability and accelerates its breakdown to creatinine. This substantially reduces creatine availability in its esterified form and as a consequence creatines such as San CM2 and CE2 are inferior to CM as a source of free creatine.