Creatine Ethyl Ester (CEE) is one of many creatine formulations developed primarily to maximize creatine absorption. One of the latest attempts to more effectively increase intramuscular creatine levels is creatine ethyl ester. Its manufacturers claim that it can by-pass the creatine transporter due to enhanced sarcolemmal (cell membrane of a muscle cell) permeability.
Creatine ethyl ester is heavily promoted as being superior to creatine monohydrate, and is claimed to have higher potency, greater absorption. We found no published data that could justify this allegation. Furthermore, esterified creatine’s stability is compromised in low pH conditions  and rapidly degrades to creatinine in stomach acid .
The purpose of study by Spillane, Mike, et al.  was to examine the effects of creatine ethyl ester supplementation in combination with heavy resistance training for 47 days compared to supplementation with creatine monohydrate (CRM) and a placebo. The recommended maintenance dose for creatine ethyl ester is 5 g. Participants in this study ingested twice the recommended dose of creatine ethyl ester, yet the creatine monohydrate group resulted in significantly higher levels of serum creatine than the CEE group (Fig. 1).
Fig. 1 – Changes in serum creatine concentrations with data expressed as mean (± SD). † indicates significantly higher serum creatine concentrations in CRT when compared to PLA (p = 0.007) and CEE (p = 0.005).
Serum creatinine was significantly greater in the CEE group compared to the placebo (p = 0.001) and CRM (p = 0.001) groups (Fig. 2). Creatinine levels for the creatine monohydrate group were elevated, but stayed within the normal range. 
Fig. 2 – Changes in serum with data expressed as mean (± SD). †
It was concluded that majority of creatine ethyl ester was degraded into creatinine in the gastrointestinal tract after supplementation.
- Mold, James D., et al. “Creatine ethyl ether.” Journal of the American Chemical Society 77.1 (1955): 178-180.
- Child, R., and M. Tallon. “Creatine ethyl ester rapidly degrades to creatinine in stomach acid.” Abstract presented at 4th annual conference of the ISSN. 2007.
Spillane, Mike, et al. “The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels.” Journal of the International Society of Sports Nutrition 6 (2009): 6.