Creatine serum supplements seem to have no effect on muscle ATP or creatine stores, despite claims by one US manufacturer, say researchers.
At a recent meeting of scientists, researchers reported that the liquid ATP Advantage Creatine Serum, manufactured by California-based Muscle Marketing USA, had no effect on 40 subjects tested.
Muscle Marketing claims that its liquid creatine serum product more effectively transports creatine to muscle than creatine monohydrate powder, commonly used to enhance athletic performance. However prior studies have shown no effect of creatine serum supplementation on blood creatine levels, noted the researchers from Baylor University and the Neurology Unit at McMaster University .
The findings, presented at the recent Experimental Biology meeting in San Diego, revealed that even when doses of creatine serum were increased to eight times the recommended dosage, they failed to have any effect on muscle ATP (adenosine triphosphate, present in all living cells as an energy source for many metabolic processes) or creatine levels.
In the study, 40 men with no history of creatine use took either 5ml of creatine serum daily for five days or a 5ml placebo. In a further test, participants increased the daily 5ml creatine serum dose to eight servings each day, with a blinded group taking the placebo in equal high dosages.
A control group ingested four 5g supplements daily of creatine monohydrate powder supplied by German firm Degussa Bioactives, who funded the study, for five days.
Results revealed that creatine monohydrate supplementation significantly increased muscle creatine content (28 per cent) while no significant differences were observed among liquid placebo or creatine serum groups in either ATP or creatine levels.
"These findings indicate that creatine serum has no effect on muscle ATP or creatine stores even when taken at eight times the recommended dosage for five days," concluded the researchers.
"The best way to determine the potential efficacy of a creatine product is to measure the effect the supplement has on increasing muscle creatine stores. Creatine monohydrate supplementation resulted in a significant increase in muscle creatine. In contrast, this study clearly indicates that low and high dose ATP Advantage Creatine Serum has no effect on muscle creatine or ATP levels," said study leader Dr Richard Krieder from the Exercise & Sport Nutrition Lab at Baylor University.
Last year Degussa BioActives' US division filed a case against Muscle Marketing to prevent it from making false claims about its creatine serum products, which Degussa claims contain only very small amounts of creatine, and more of an undesirable degradation product, creatinine.