A recent investigation conducted by the Food and Drug Administration has revealed that many herbal or “all-natural” remedies for erectile dysfunction not only contain the same active ingredient found in Viagra, but in some cases have double the dosage a doctor would prescribe.

As reported by BuzzFeed, in the past week as many as 25 “natural supplements” meant to treat erectile dysfunction were found to contain sildenafil citrate, the same active ingredient found in prescription drugs such as Viagra.

Despite an obvious attempt at falsely advertising a prescription drug as an herbal remedy, the unregulated tainted supplements could cause serious harm and even death to those who unknowingly buy them. According to Pieter Cohen, an assistant professor of medicine at the Cambridge Health Alliance who specializes in the supplement industry, it’s not just small amounts of the drug that the FDA is uncovering.

“FDA doesn’t say how much they’ve found, but whenever we’ve taken a look at this, these dosages are really significant,” he said. “They can contain dosages twice as high as Viagra itself.”

Natural erectile dysfunction supplements are both one of the biggest sellers on the market for herbal treatments and one of the most likely to be tainted. It's suspected the FDA has only hit the tip of the iceberg regarding the current investigation into herbal erectile dysfunction, and that the same manufacturers are also counterfeiting other herbal remedies and even counterfeiting prescription drugs.

The World Health Organization describes counterfeit drugs as a widespread problem, but it occurs most often in developing countries. For example, one study from 2012 found that around one-third of all available malaria medications sold in Asia and sub-Saharan Africa were counterfeit. A press release from the University of Michigan stated that counterfeit drugs kill around 700,000 people every year.

The FDA declined to release details on the source of these supplements, such as whether they all came from a single shipment or are part of an in-depth counterfeit drug ring. Cohen told BuzzFeed that regardless of their origins, one thing's for sure: These contaminated sex-enhancement supplements seem to be on the rise. BuzzFeed also reported that it’s likely the same factories producing counterfeit ED supplements are also creating dietary supplements.

There is hope, though. Last year Pfizer made $1.7 billion off of Viagra sales. This large monetary stake that companies such as Pfizer have in prescription erectile dysfunction medication could be enough to push the regulation of fake drugs to priority level. According to Jezebel, drug-mogul Pfizer already has "vested interest in rooting out fake versions of Viagra."