Photo of a V8 dietary supplement, which hospitalized 17 men with severe hypoglycemia
Photo: CDC

Last fall 17 men in Virginia were hospitalized with severe—and for some, life-threatening—hypoglycemia, or low blood glucose levels, after taking a dietary supplement promoted for male sexual enhancement. Within days of the first reports, state health authorities alerted the public about the product, which is called V8 and was generally sold at convenience stores and gas stations in Virginia. V8 was removed from store shelves when it was found.

An analysis later determined that the supplement contained the prescription drugs sildenafil, the generic form of Viagra, which is used to treat erectile dysfunction, and glyburide, which is used to treat diabetes, according to a report published last week by the Centers for Disease Control and Prevention.

But 10 months since the outbreak began, the Food and Drug Administration, which regulates the $45 billion supplement industry in the U.S., is still investigating the origin of V8, the CDC report says.

The delay highlights the urgent need for the FDA to create a mandatory product registry for supplements that includes manufacturer and product ingredient and label information, advocates and researchers say, because it would allow the agency to respond more effectively when an outbreak occurs. 

More on Dietary Supplements

“Without an FDA registry of supplement products, the FDA has no idea what is even on the market” or who makes it, says Pieter Cohen, M.D., an internist at the Harvard Medical School who has studied supplements. “This makes the agency's job of trying to remove dangerous supplements particularly challenging.”

The New England Journal of Medicine published an article in December by Cohen and others that advanced the idea of a registry and said that such a database could be useful to consumers as well. They could use it to immediately confirm that a product’s manufacturer had properly registered it with the FDA. If a product wasn’t registered, that could be a red flag.

Industry groups agree, and point out that the FDA has also proposed that products marketed as dietary supplements be listed in a database, and that the agency have the authority to act against manufacturers of products that aren’t on the list. But the process has yet to move beyond the proposal stage.

Steve Mister, president and CEO of the Council for Responsible Nutrition (CRN), agrees that the FDA would benefit from such a listing.

“A mandatory product listing can help FDA to effectively identify and remove irresponsible actors in the market that threaten both the health and safety of consumers and the reputation of the responsible marketplace,” Mister says.  

The FDA wouldn’t comment on the delay, saying it can’t discuss “possible or ongoing compliance matters except with the party involved.” But the agency says a mandatory registry would improve its capabilities to police the supplement market. 

“Mandatory listing of products marketed as dietary supplements would allow the FDA to know when new products are introduced, quickly identify and act against dangerous or otherwise illegal products, improve transparency, and promote risk-based regulation,” it says.

A 'Hunch' Points to V8

John Downs, M.D., a fellow at the Virginia Poison Center, took a call last August from the emergency physician who handled the first case in the outbreak. The patient was a 57-year-old man who didn't have diabetes and had no known exposure to insulin or other medications that can lower blood sugar levels. 

The man reported he’d been unable to fill his usual sildenafil prescription because of health insurance difficulties. Instead, he bought the V8 supplement and took it every night between Aug. 10 and Aug. 12. The emergency physician had a “hunch” that the man’s symptoms were related to V8, Downs says, “because that was the only thing this patient had taken recently that was new for him.” 

Downs and the physician reviewed the medical literature and found a review of a 2009 outbreak of hypoglycemia associated with sildenafil that had been contaminated with glyburide. As a result, the pair suspected the man was suffering from an overdose of antidiabetic meds, and collected the V8 product for testing. 

Laboratory tests following the more recent outbreak confirmed that all samples of V8 contained sildenafil ranging from 55 to 156 mg per tablet. And most contained 90 to 100 mg of glyburide, “a dose 5 to 10 times higher than that used in the treatment of diabetes,” the CDC report says.

“Patients reported that the supplement was promoted by word of mouth and was purported to enhance male sexual performance.” 

The Investigation Is 'Ongoing'

Downs notes that the FDA was involved early and helped state officials track down stores that were selling V8. State health authorities issued warnings to the public within days of the first reports of patients. The FDA investigation into who manufactured the product is ongoing, the CDC report says. 

While a product registry would aid consumers who may be purchasing supplements by increasing transparency, it doesn’t necessarily ensure that a product is safe. Under federal law, there’s generally no requirement for supplements to be proved safe and effective before they're permitted on the market. 

Industry groups like CRN support increased funding for the FDA to improve oversight of supplements. CR’s advocates have repeatedly echoed those calls. 

“For many years, Consumer Reports has urged consumers to avoid herbal supplements marketed for sexual enhancement, because literally hundreds of these products have been found to be spiked with prescription drugs,” says Chuck Bell, who has led CR's advocacy work on dietary supplements for more than 20 years. “We should have zero tolerance for the extremely reckless and dangerous practice of illegally adding prescription drugs to dietary supplements. This isn’t a gray area in the law. It’s a flagrant violation of it.”

The FDA urges consumers to file a report if they experience an adverse event after taking a product. But the agency’s ability to analyze those reports has shortcomings, so advocates and researchers advise caution if you decide to take a supplement, especially if you also take prescription drugs 

“For consumers who are on other medications, particularly cardiac medications, the interactions [of supplements] can really be life-threatening,” Downs says.