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Glycosylated Creatine

Fulzen

Fulzen

New Member
May 26, 2016
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1
#1
The use of Polyethylene Glycol (PEG) in creatine supplementation

“PEGylation” is the term used to denote the binding of polyethylene glycol (PEG) to another molecule.
PEG is an organic, water-soluble compound used in a variety of chemical, biological, industrial, and commercial applications.

Some people may recognize that PEG is the main ingredient in OTC stool softeners like MiraLax (mainly due to its hydrophilic nature). The absorption-enhancing effect PEG produces makes it a superb excipient for pharmaceuticals and other molecules. PEG is also rather safe and has a low toxicity.

Research findings behind PEGylated creatine

While the literature on PEGylated creatine is still somewhat in its infancy, the few studies that have been completed do show quite a bit of promise. In fact, they seem to suggest that polyethylene glycosylated creatine is just as effective as creatine monohydrate at doses 75% less than that of monohydrate treatments. [1,2]

This would suggest that PEG acts as to increase the efficacy of oral creatine supplements. The mechanism for this is believed to be due to the enhanced gastrointestinal (GI) absorption of PEGylated creatine by increasing permeability coefficients in the GI tract and across the sarcolemma.[3] Therefore, smaller doses of PEGylated creatine should, theoretically, result in equivalent intramuscular phosphocreatine concentrations when compared with ingestion of a larger dose of creatine monohydrate.

Figure 1 below shows the results of a 2009 study by Herda et. al that compared small-dose and moderate-dose PEGylated creatine supplementation (1.25g and 2.50g, respectively) vs. 5g of creatine monohydrate supplementation. The pre- and post-supplementation periods were 30 days apart, and performance was assessed before and after these periods.

PEG1.jpg


While PEGylated creatine did not quite match the absolute percent changes as creatine monohydrate in most tests, it still had notable effects on performance. Moreover, the doses of PEGylated creatine used were significantly lower than that of creatine monohydrate (75 and 50% less to be exact).

The other thing to consider here is that the subjects in the creatine monohydrate gained an average of 2.2lbs over the course of the supplementation period, whereas subjects in the PEGylated creatine groups only gained about 1lb. Therefore, the “relative” strength change of those in the PEGylated creatine groups was very similar to that of the creatine monohydrate group.

Furthermore, a study 2010 study by Camic et. al found that PEGylated creatine dosed at 5g per day for 28 days resulted in a significant increase in 1 rep maximums on the bench press of subjects, even in the absence of strength training.

So is PEGylated creatine better than creatine monohydrate?

At this point in time, PEGylated creatine shows promise both in anecdote and theory, but the research available is rather limited and very few products on the market incorporate it. This isn’t to say that PEGylated creatine is an inferior form of creatine, but we will just have to keep holding our breath and see if it really ever lives up to the hype. Until then, you really can’t go wrong with creatine monohydrate.

References:
1. Herda TJ, Beck TW, Ryan ED, Smith AE, Walter AA, Hartman MJ, Stout JR, Cramer JT:Effects of creatine monohydrate and polyethylene glycosylated creatine supplementation on muscular strength, endurance, and power output. J Strength Cond Res 2009, 23:818-826.
2. Camic CL, Hendrix CR, Housh TJ, Zuniga JM, Mielke M, Johnson GO, Schmidt RJ, Housh DJ:The effects of polyethylene glycosylated creatine supplementation on muscular strength and power. J Strength Cond Res 2010, 24:3343-3351
3. Fry, CF, Moore, CA, Lohnes, CA, and Deangelis, D. Modified creatine compound enhances skeletal muscle uptake during dietary supplementation. J Strength Cond Res 21: e5, 2007.
 
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