Originally Posted by Dr. Stout

There are three senarios for CEE

1) CEE is a true covalently bonded ester and is absorbed into blood and tissues as the intact molecule. This is the picture that the manufacturers would have us believe and is the basis for why they claim CEE is superior to creatine monohydrate. However, inside cells CEE will be unreactive with creatine kinase and may be a potential competitive or non-competitive inhibitor to the enzyme. This would make it toxic to brain, heart, testes, muscle and all other CK containing tissues. People by now should be dying, but clearly are not and this means 2) and 3) are the more likely.

Nonethess, CEE should be treated as a potentially toxic phrarmaceutical and in the US should be treated as a drug, which requires multi species studies to estimate LD50's and potential sites of tissue damage etc. However, recently I have
been told that CEE did get new dietary ingredient status (scary).

2) CEE is hydrolysed to creatine on absorption from the gut. In this case CEE offers no advantage over creatine monohydrate which has a bioavilability of 100%. Indeed if hydrolysis of CEE is less than 100% then it will be inferior to the monohydate. But in the case of hydrolysis there are no circumstances in which it could be better than the monohydrate in increasing tissue creatine levels. Obviously CEE manufacturers would prefer 1) except that they then shoot themselves in the foot over the issue of potential toxicity.

3) CEE is not a true covalently bonded ester. The whole of this is a scam with the compound ionising in solution to free creatine, as does the monohydrate and all salts of creatine. In this case CEE would again represent no advantage over creatine monohydrate, except to the seller who can double the price.

The failure of the US sports nutrition community (industry and the universities) to call for closer examination of CEE seriously questions its credibility in the eyes of many scientist in this country and the world. A simple water solvation test would answer 3), i.e. whether or not it was a covalent or ionisable derivative of creatine. The work time would be about one
hour. Investigation of whether CEE is a competitive or non-competitive inhibitor of creatine kinase would take 2-3 hours. If either of these occured then clearly CEE must be investigated in at least two species to investigate lethality and potential organ damage. If on the other hand CEE is ionisable then I see no reason why a bioavailability study should not be undertaken comparing this, on a molar/molar basis, with creatine monohydrate. My guess is that plasma AUC would be identical.
Again a very simple study.

None of this is rocket science but could spare a few lives, if the
manufacturers claims on the absorption of CEE are to believed.

OH! and one more thought: Another aspect to consider is how CEE would overcome a huge concentration gradient from circulation to muscle if it does not use the creatine transporter and uses simple diffusion as they promote.

Bottom Line: I say stay with good old GERMAN creatine Monohydrate. 500 human studies can't be wrong. :-)