There has been a nationwide recall of tainted herbal dietary supplements after they were found to contain hidden drug ingredients. The U.S. Food and Drug Administration (FDA) has described the tainted product as a "serious threat."

Georgia-based supplement company GURU INC. voluntarily recalled a batch of Infla-650 herbal supplements on July 16 after they were found to contain acetaminophen, diclofenac and phenylbutazone, which were not listed on packaging. The product is marketed as an herbal dietary supplement for pain relief and reducing inflammation.

"Use of the product poses a serious threat to consumers," the FDA said in a statement.

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The "hidden drugs" were first identified by the FDA on June 20 following routine tests.

An image shows Infla-650 capsules. Supplement company GURU INC. has voluntarily recalled a batch of Infla-650 herbal supplements after they were found to contain ingredients that were not listed on packaging. An image shows Infla-650 capsules. Supplement company GURU INC. has voluntarily recalled a batch of Infla-650 herbal supplements after they were found to contain ingredients that were not listed on packaging. FDA

Acetaminophen is the active ingredient of paracetamol, a commonly used pain killer. While the drug is safe to take in small quantities, the FDA said that the use of the tainted Infla-650 supplements posed a "serious threat" of unintentional overdose, which can cause severe liver damage and serious skin reactions.

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Diclofenac is an anti-inflammatory prescription drug that may increase the risk of cardiovascular events and gastrointestinal damage when taken in high concentrations. It can also interact with other medications.

Phenylbutazone, the most concerning of the "hidden drugs," was discontinued for human use in the U.S. because of health risks.

"The most serious and life-threatening injury associated with phenylbutazone treatment is bone marrow toxicity, which occurs when the body does not produce enough red blood cells, white blood cells, and/or platelets," according to the FDA. "Patients with anemia, low white or red blood cell count, or decreased blood platelets may be at a greater risk of death or serious injury."

To date GURU INC. has not received any reports of adverse side effects related to this recall. The company has notified distributors and customers of the recall by email and has urged consumers to stop using the product.

Newsweek contacted GURU INC. via email.

Infla-650 contains a blend of herbs—based on the ancient Indian system of medicine known as Ayurveda—including ashwagandha, fenugreek seed and shilajit.

The FDA warned that Infla-650 and many other dietary supplements are classed as "unapproved" drugs and have not undergone the same level of safety and efficacy scrutiny as approved pharmaceutical products.

"FDA is unable to test and identify all products marketed as dietary supplements that have potentially harmful hidden ingredients," the administration said in a statement on June 20 after the hidden drugs were first detected. "Consumers should exercise caution."

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