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 in the US, researchers reported that the liquid ATP Advantage Creatine Serum, manufactured by California-based Muscle Marketing USA, had no effect on 40 subjects tested.
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, funded by German company Degussa BioActives, 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 equally high dosages.
A control group ingested four 5g supplements daily of creatine monohydrate powder supplied by Degussa Bioactives 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.