The State of Oregon filed a lawsuit against dietary supplements retailer GNC on Thursday, alleging that the retailer knowingly sold supplements that contained illegal and dangerous substances. The suit alleges that GNC knowingly violated Oregon’s Unlawful Trade Practices Act and, in doing so, endangered consumers of their dietary supplements.

The substances in question, picamilon and Beta-methylphenethylamine (BMPEA), were found in numerous supplements GNC sold at its 25 Oregon locations. Picamilon is a synthetic drug, according to the lawsuit, which was designed and developed by researchers in the former Soviet Union. Today, it’s used as a prescription drug in Russia, but it has never been approved for use in the U.S. The FDA considers it unsafe.

“When GNC sold products in Oregon that contained BMPEA, GNC misrepresented that the product was a lawful dietary supplement that only contained lawful dietary ingredients,” the complaint reads.

BMPEA, on the other hand, is a chemical similar in structure to amphetamine. According to the suit, it was first created in the 1930s and never went through clinical trials on humans. The effects, according to Forbes, include massively increased blood pressure, which puts undue stress on the heart and can induce cardiac arrest in vulnerable individuals.

Between the two substances, BMPEA is more dangerous, as it has never been tested on humans and its effects are largely unknown. It has never been tested for safety. It has been seen to increase blood pressure in dogs and cats, and hundreds of people are sent to emergency rooms every year after having ingested the substance.

“It’s scary to know that certain products sold by GNC contain an ingredient that is not even labeled – yet alone approved in the United States,” Oregon Attorney General Rosenblum said in a statement.

Herbal supplements are stocked and sold throughout the US, often without a prescription

GNC stocked and sold supplements containing both ingredients, and according to the lawsuit, from 2013 to 2015, GNC Vice President David J. Sullivan knew about the illegal contents and chose to keep them on the shelves. The lawsuit filed by Oregon Attorney General Ellen Rosenblum contains pages of emails between GNC’s upper management discussing the illegal ingredients.

“Despite widespread knowledge that Acacia rigidula (or AR) products sold by GNC were at high risk of having been spiked with BMPEA, David J. Sullivan continued to sell products that contained AR without testing these products to determine whether it was adulterated with BMPEA,” the suit reads.

This is just the latest in a fight that has been going on for years between state and federal officials and supplements retailers like GNC. The FDA alleges that many supposedly natural supplements often contain ingredients found in prescription drugs, and oftentimes these ingredients are not labeled and their risks are never disclosed to consumers. In April, the FDA sent letters to five U.S. companies instructing them to immediately cease the manufacture and sale of their products that tested positive for BMPEA.

GNC stocks sunk due to a new law suit in Oregon. [Photo by Andrew Burton/Getty Images]

When initially reached for comment on the suit, GNC told NBC News that the company doesn’t comment on pending litigation. As soon as the suit was filed, however, GNC’s stock price tanked, reaching its 52-week low within minutes.

“The claims made by the Oregon Attorney General are without merit and GNC intends to vigorously defend against these allegations,” GNC told Business Insider after its stock price fell Friday.

This isn’t the first time GNC has found itself in hot water with state and federal regulators. In 2013, an Army Private named Michael Lee Sparling suffered cardiac arrest and died just 10 minutes into a morning run after having ingested a supplement purchased from GNC. The private’s family filed a lawsuit against GNC, alleging that the supplement was the direct cause of their son’s death.

GNC continued to deny that the supplement played any role in the Private’s death, but the company paid out $2 million to settle the class-action lawsuit.

[Photos via Getty Images]