What's in that delicious chicken wing you're gnawing? Chicken, you say? Yes, but among the herbs and spices might also be arsenic, Prozac, caffeine, Tylenol, Benadryl and banned antibiotics like Cipro, according to Mother Nature Network.

Two new studies conducted by scientists at Johns Hopkins' Bloomberg School of Public Health and Arizona State University found that chickens and turkeys from factory farms may be dosed up with an assortment of chemicals, including antibiotics that have been banned from use in poultry since 2005.

The levels of these substances aren't “an immediate health concern,” co-author Keeve E. Nachman of Johns Hopkins told the New York Times on April 4, but added that he and his fellow scientists were “floored” by what they found.

The annual per capita human consumption of poultry products is approximately 100 lbs., greater than that of any other animal- or vegetable-derived protein source in the U.S.

The studies, published in the journals Environmental Science & Technology and Science of the Total Environment, didn't study chicken meat but instead examined feather meal, a byproduct of poultry processing. Various chemicals have the the potential to “bioaccumulate” in poultry feathers, according to the first study–meaning if they're in the feathers, they're also in the flesh. Furthermore, feather meal is a common additive to chicken, swine, cattle and fish feed.

The feather meal samples tested routinely contained the banned antibiotics known as fluoroquinolones, such as the drug Cipro. Fluoroquinolones — a class of antibiotics used to treat serious bacterial infections in people, particularly infections that are resistant to older classes of antibiotics — were banned from use in poultry because they can breed antibiotic-resistant “superbugs.” Researchers found fluoroquinolones in eight of 12 samples of feather meal from six different states.

“The discovery of certain antibiotics in feather meal strongly suggests the continued use of these drugs, despite the ban put in place in 2005 by the FDA,” the study's lead author, Bloomberg School microbiologist David Love, said in a statement. “The public health community has long been frustrated with the unwillingness of FDA to effectively address what antibiotics are fed to food animals.”

Most samples also contained caffeine, and one third contained the active antihistamine ingredient found in Benadryl. Many samples also contained acetaminophen (the active ingredient in Tylenol). Samples tested that originated in China also contained the active ingredient in the antidepressant Prozac.

The second study found that virtually every sample studied contained Roxarsone, an arsenic compound.

“This study reveals yet another pathway of unwanted human exposure to a surprisingly broad spectrum of prescription and over-the-counter drugs,” noted study co-author Rolf Halden, associate director of the Swette Center for Environmental Biotechnology at Arizona State University.

Why are chickens so drugged up? The caffeine (from coffee grounds and green tea powder) keeps them awake so they eat more. The Benadryl, acetaminophen and Prozac reduce their anxiety in order to speed up their growth and improve the taste of their meat. Arsenic is used to reduce infections and give the meat a nice pink color.

The researchers say the continued use of banned antibiotics could explain why drug-resistant superbugs are still at high levels in commercial poultry more than half a decade after the ban was put in place. They also say the arsenic “may pose additional risks to humans as a result of [feather meal's] use as an organic fertilizer and when animal waste is managed.”

“Based on what we've learned, I'm concerned that the new FDA guidance documents, which call for voluntary action from industry, will be ineffectual,” Nachman said. “By looking into feather meal, and uncovering a drug banned nearly six years ago, we have very little confidence that the food animal production industry can be left to regulate itself.”

“I've been studying food-animal production for some time, and the more I study, the more I'm drawn to organic,” he told the Times.

On the other hand, if you're feeling down, have a headache and are suffering from seasonal allergies, a nice big plate of factory-farmed fried chicken might be just the ticket.

Follow Samantha Bonar @samanthabonar.