Yet dietary supplements don't have the scrutiny given to prescription drugs. Is certifying supplements the answer?
"One of the athletic trainers at the sport clinic said, 'Hey, I have an athlete that passed out in the weight room and we have no idea why,'" said registered dietitian Ellen Coleman, an expert on supplements.
Coleman says products like protein powder might appear safe but in fact may be spiked with banned substances or bear names that sound perfectly natural, yet could provide unwanted physical effects.
"It's making their heart go whacko and we've had some kids that have had some huge problems with that," said Jim Clover, coordinator of The SPORT Clinic in Riverside.
Ingredients like yohimbine or citrus aurantium (bitter orange) are considered ephedra's baby brother.
And now there's another popular ingredient: geranium oil. It sounds benign, but it's actually dimethylhexanamine, often seen as 1,3 DMAA, a stimulant that is to amphetamine- or ephedrine-like in nature.
"Sometimes the stimulant may be declared on the label, but the athlete doesn't know that it is a stimulant that could cause them to flunk a doping exam," said Coleman. That would leave them suspended for a year or more.
In the case of a weekend warrior who's overweight or hyper-tense, the side effects might be worse.
"Heart attack, stroke, seizure and death," said Coleman.
And consumers need to realize that the Food and Drug Administration (FDA) doesn't test these products prior to market.
"There are several hundred products still out on the market that contain undisclosed anabolic steroids," said Coleman.
In addition, many products have a cocktail of ingredients combined together called a proprietary blend. That's the manufacturer's "secret recipe," so to speak. So look for unknown ingredients or a load of stimulants. It's your job to keep shopping.
"The athlete definitely has to do some research on the different ingredients, and then even talk with the company," said Scott Momii, executive director of product management, Max International, a supplement manufacturer.
Momii says your best bet is buying products certified by an outside agency.
"They'll test for heavy metals, pesticides, herbicides. They take the most comprehensive list available of banned substances and they test for that," said Momii.
"The company that really pioneered sports-supplement certification is EAS. They are very well-known for products such as Myoplex and their whey protein and Phosphagain," said Coleman.
Companies like NSF Certified for Sport, and HFL Certified are widely respected, but there are others as well.
"Even if it's not a doping issue, it's a safety issue," said Coleman.
