The U.S. Food and Drug Administration (FDA) issued warning letters to four companies for illegally selling tainted honey-based products that may pose a significant health risk to consumers in addition to publishing Public Notifications of 18 honey-based products. The FDA’s laboratory testing found that product samples contained active drug ingredients not listed on the product labels, including the active drug ingredients found in Cialis (tadalafil) and Viagra (sildenafil), which are FDA approved drugs used to treat men with erectile dysfunction.

Sildenafil and tadalafil are restricted to use under the supervision of a licensed health care professional. These undeclared ingredients may interact with nitrates found in some prescription drugs, such as nitroglycerin, and may lower blood pressure to dangerous levels. People with diabetes, high blood pressure, high cholesterol, or heart disease often take nitrates.