The U.S. Food and Drug Administration (FDA) has found that Imperial Extreme 2000mg capsules have been tainted with undeclared sildenafil (Viagra) and tadalafil (Cialis).

S&B Shopper LLC has voluntarily been recalling all lots of Imperial Extreme 2000mg capsules, to the consumer level, according to the FDA.

Sildenafil and tadalafil belong to the class of drugs called phosphodiesterase (PDE-5) inhibitors, which are prescription-only drugs advised for the treatment of erectile dysfunction (ED) in men.

On its website, the FDA released a risk statement, “Consumers with underlying medical issues who take Imperial Extreme 2000mg capsules with undeclared sildenafil and tadalafil may experience serious health risks.”

PDE-5 inhibitors may adversely interact with certain prescription drugs containing nitrates or alpha-blockers. A combination of these drugs could lower blood pressure to potentially dangerous levels, which could be life-threatening.

Imperial Extreme capsules are sold as a dietary supplement for male sexual enhancement. The product was sold online and fulfilled by amazon on its website.

In December, the FDA issued a press release, in which it warned consumers to avoid nearly 50 male sexual enhancement products sold on Amazon and eBay because they were tainted with potentially harmful ingredients.

The FDA said S&B Shopper LLC is notifying its customers and distributors by contacting buyers through Amazon. Consumers who bought Imperial Extreme 2000mg capsules should stop using and destroy them.

“Consumers should contact their physician or healthcare provider if they have experienced any problems that may be related to using these drug products,” the agency wrote on its website. People who experience any kind of adverse reactions or quality problems after using the product should report to the FDA’s MedWatch Adverse Event Reporting program.