Most people love coffee—but some people really love a strong brew with a buzz that lasts for hours. This goes doubly true for consumers of Stiff Bull Herbal Coffee, otherwise known as the Viagra of coffee, which promises to give you a rise when you need one. How is Stiff Bull Herbal Coffee different than, say, a regular cup of single-origin Arabica? It boasts a whole heap of herbal ingredients promised to provide "energy" by way of Tongkat Ali, Maca Root, and Guarana. But these ingredients aren't what set the Food and Drug Administration's sights on Stiff Bull Herbal Coffee's operation.

The real ingredient that is raising eyebrows (among other body parts) is desmethyl carbodenafil, a chemical that behaves similarly to sildenafil citrate, the main ingredient in Viagra that provides, well, a liftBut for people with high blood pressure, diabetes, or heart disease, desmethyl carbodenafil can be life-threatening if not pre-approved by a doctor. And since the ingredients in Stiff Bull Herbal Coffee are technically herbal remedies, they do not need to obtain FDA clearance or inspection. That's the same reason you can buy melatonin and drink kava in the United States without a prescription—legal loopholes for the win!

But even though the FDA doesn't usually wade into the murky waters of herbal and dietary supplements, it did provide a warning for Stiff Bull Herbal Coffee that strongly recommended people not to put it through their French press and swig a few cups. The FDA statement focused on the product's inclusion of desmethyl carbodenafil, which isn't even labeled on the packaging as an ingredient. 

“This undeclared ingredient may interact with nitrates found in some prescription drugs such as nitroglycerin and may lower blood pressure to dangerous levels. Men with diabetes, high blood pressure, high cholesterol or heart disease often take nitrates,” the administration warned

The biggest takeaway here is that not all "herbal" products are safe, and that the term "natural" doesn't have any legal or scientific meaning when it comes to food and beverages. If anything, herbal products are often given much more leeway than FDA-regulated goods, meaning that manufacturers could put just about anything that isn't explicitly illegal inside of their products. So if you're seeking a way to keep that morning wood going well into the afternoon, you might want to look somewhere other than your coffee pot.