Muscle-building supplements with creatine flunk tests
ConsumerLab.com, a provider of information and evaluations of products that affect health and nutrition, tested 13 popular supplements and found quality problems with three, a nearly 1 in 4 ratio.
One supplement, the liquid DiMaxx Muscle Creatine Plus, was contaminated with 32 mg of creatinine, a by-product formed when creatine is absorbed and metabolized in the body. The creatinine initially present in the bottle amounted to 7% of the amount of actual creatine, many times higher than the 0.1% ConsumerLab recommends.
The other supplement with inadequate levels of creatine, Muscle Marketing USA's ATP Creatine Serum, claimed to contain 250mg of a proprietary creatine phosphate serum complex per 5ml serving. But it did not disclose the actual amount of creatine. Testing found a mere 20.7 mg of creatine in the product, also sold in liquid form, or less than 10% of the amount of the complex.
This amount is significantly lower than typically used, according to ConsumerLab. Furthermore, a high amount of creatinine -- 47 mg, or more than twice the amount of actual creatine -- was detected. The bottom line is that the 250 mg serum "complex" only contained about 68 mg of creatine - 27% of the claimed "complex."
"The most common way of using creatine is as a powder, which is then mixed with liquid. But in the world of supplements, people are often looking for a more convenient form, where they don't always have to mix a drink," said Dr. Tod Cooperman, president of ConsumerLab, noting that both failed products were sold as liquids.
Creatine is mostly used by competitive athletes and to build endurance during exercises of short duration, such as weight-lifting and sprinting. Most creatine supplements feature anywhere between 5 and 20 grams of creatine per daily serving. While creatinine in small amounts does not pose a health risk, it provides no benefits or enhancement, either, as it is eliminated through the kidneys. High levels of creatinine, though, can be an extra burden on the kidneys; common blood tests check for it because its percentage in the blood is an indicator of kidney function.
"Many people use creatine just on the belief that it's going to make them stronger or have bigger muscles, so they often go out and buy a supplement based on some general information they receive, assuming that any product out there is going to deliver an appropriate dose," said Cooperman. "But neither of those products have anywhere near the amount of creatine that's typically used."
The third product, Dymatize Nutrition's BCAA Complex 5050 Branched Chain Amino Acids, failed testing because it contained only 86.1% of its claimed isoleucine. Isoleucine is one of the three essential amino acids (along with leucine and valine) that the body cannot produce and needs from dietary sources. For a supplement of this kind to be effective, a ratio of 2:1:1 (leucine: isoleucine: valine) is typically recommended.
ConsumerLab is not universally accepted as an authority since the company sells memberships to companies whose products are reviewed.