A nice article in the August issue of the International Journal of Sport Nutrition and Exercise Metabolism titled Effect of creatine supplementation and resistance-exercise training on muscle insulin-like growth factor in young adults looked at the effects on Insulin-like Growth Factor-I (IGF-I) levels in people combining 30 minutes of exercise 3-5 times per week with with supplemental creatine. They found a significant increase in IGF-I in those taking creatine.

Their subjects took 0.25g / kg lean tissue mass / day creatine monohydrate (that sounds like a fair bit, for me at 80kg that’d be up to 20g/day).

Personally, I have been taking creatine ethyl ester (CEE), which is a popular alternative to creatine monohydrate (CM) because it is supposedly more bioavailable and has a longer half-life. Based on this information and other recommendations, I have been taking around 4g/day CEE.

However, looking into things now, it appears that to date, none of these claims have been evaluated by an independent or university laboratory, and no data are available comparing CEE and CM.

In fact, this study claims that the addition of the ethyl ester actually accelerates CEE’s breakdown in the stomach, making it less bioavailable than 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 (products containing CEE) are inferior to CM as a source of free creatine.

Interesting! So, perhaps one should switch back to CM and up the daily dose to the astronomical levels suggested! However, if CM tastes anything like CEE, I don’t know if this will be possible. It’s probably the most rank substance I have ever supplemented with, so I’m not all that enthused about the prospect.

A good place to get CEE and CM is BulkNutrition.com.