Are drugs lurking in your dietary supplements?

Another day, another safety alert from the FDA that a so-called dietary supplement or natural herbal remedy actually contains a drug. That’s the eighth such warning in the last three months (see FDA warnings). The latest one warns that products marketed as “natural testosterone boosters” or sex enhancers, including Arom-X, 4-AD, Decavol, and Reversitol, contain an aromatase inhibitor. This drug, which is used to treat some kinds of breast and ovarian cancer, blocks the body from making estrogen, a hormone needed by both men and women. According to the FDA, unapproved use of an aromatase inhibitor can lead to “decreased rate of bone maturation and growth, decreased sperm production, infertility, aggressive behavior, adrenal insufficiency, kidney failure, and liver dysfunction.” People with liver, kidney, adrenal, or prostate problems are at higher risk for getting into trouble with an aromatase inhibitor. The FDA says that “products containing aromatase inhibitors have a reasonable probability of resulting in permanent impairment of a body structure or function in at risk consumers.”

Earlier alerts warn that some “natural” supplements contain sildenafil or tadalafil (the active ingredients in Viagra and Cialis, prescription drugs used to treat erectile dysfunction) or compounds that are chemically similar to them. These substances interact with nitrates found in prescription drugs commonly taken by men with heart disease, and can dangerously lower blood pressure. Others warn of the presence of sibutramine (the active ingredient in Meridia, a prescription weight-loss drug) or compounds that mimic it.

These warnings highlight the sleazy underside of the dietary supplement industry. Some companies slip drugs into their “natural” remedies so they’ll work as advertised. Others allow them in through shoddy manufacturing processes.

How can this happen? Back in 1994, Congress passed the Dietary Supplement Health and Education Act (DSHEA). In a nutshell, it said that manufacturers could make and sell loosely defined “dietary supplements” with little or no testing beforehand, and that the products are assumed to be safe and effective unless the government proves otherwise. That’s in stark contrast to the testing and safety process that new and existing drugs must go through, overseen every step of the way by the FDA. Pharmaceutical companies must prove a drug is both safe and effective, and will be carefully and properly made, before it’s allowed onto the market.

I’m not an anti-supplement agitator. I take a multivitamin every day. I believe that many supplement makers and promoters are honest and are working to improve public health. I also think that some herbs or plant extracts are good for preventing or treating some diseases. But they almost certainly affect how the body works just as prescription drugs do, so they should be governed by the same set of rules and regulations.

In February 2004, the FDA banned sales of dietary supplements containing ephedra, also called Ma huang. But it took the FDA more than seven years to gather the evidence to support this move. During that time, it received 16,000 reports of injuries, 62,000 consumer complaints, and at least 155 deaths related to ephedra-containing products. It shouldn’t take that long, or umpteen safety alerts, to ensure that dietary supplements are safe.

Senators John McCain and Byron Dorgan have introduced a bill into the Senate that could bring a small bit of order to the Wild West of dietary supplements. In the mean time, your safest bet is to buy only dietary supplements that carry a seal from the U.S. Pharmacopeia’s Dietary Supplement Verification Program. It verifies the quality, purity, and potency of dietary supplements. (Click here to see a list of USP verified dietary supplements.) But the USP seal doesn’t vouch for the effectiveness of the product. In that regard, it’s still caveat emptor—let the buyer beware.