The adage “all attention is good attention” may be true for marketers — not so for the Sonoran Desert toad. Last fall, the U.S. National Park Service sent out a message on Facebook asking visitors to “refrain from licking” the toad (technically Incilius alvarius but commonly called Bufo alvarius).

That message came months after a New York Times article covered the booming interest in the psychedelic compound that the toad excretes from its skin — along with the “poaching, over-harvesting and illegal trafficking” that have accompanied that interest. People don’t typically lick the toads to get high, says Robert Villa, a community outreach specialist at the University of Arizona’s Desert Laboratory on Tumamoc Hill. The secretions the toads produce are toxic when ingested. They “work orally, through the mucous membranes, and cause really dangerous side effects, like cardiac arrest,” Villa says.

Instead, for decades, people have been collecting the secretions, then drying and smoking them. When inhaled, a compound within, 5-MeO-DMT, can cause auditory and visual hallucinations. “It’s a very powerful psychedelic sometimes called the ‘God molecule,’ ” says pharmacologist and chemist David Nichols of Purdue University in West Lafayette, Ind. The drug’s growing popularity could be bad news for toad populations. “If you relocate it outside of its home territory,” Villa says, which often happens when people collect a toad for its secretions, “it gets lost and its chances for survival go way down.” What’s more, collecting large numbers of toads increases the risk of disease transmission, like chytrid fungus, between toads.

The Sonoran Desert toad secretes an enzyme that converts bufotenine, a compound also made by other toads, into 5-MeO-DMT, a powerful hallucinogen related to the psychedelic drug DMT. All toads secrete toxins from their skin. These secretions, whose specific compounds vary from species to species, probably evolved as a way to keep a toad’s body moist. Over time, the compounds, which can also act on the brain and affect heart muscle when ingested, came to aid in self-defense. But the Sonoran Desert toad, also known as the Colorado River toad, appears to have taken evolution one step further.

The toad, one of the largest in North America, secretes an enzyme that converts bufotenine, a compound also made by other toads, into 5-MeO-DMT, a powerful hallucinogen related to the psychedelic drug DMT. A frightened Sonoran Desert toad gushes its toxic mix, which includes 5-MeO-DMT, from its parotoid glands — located behind each eye — and from glands on its legs. It’s a way to say, “Please don’t eat me! I don’t taste good!” When swallowed in large quantities by a potential predator, the toxins can cause coma, cardiac arrest and even death.

Scientists aren’t yet sure why the Sonoran Desert toad produces 5-MeO-DMT, and why it is the only toad known to make it. “There’s a lot of mystery,” Villa says. Some people who use kambô, the toxic secretion produced by the giant monkey frog, report having spiritual experiences. There’s no scientific consensus on whether kambô, the name for the toxic secretion produced by the giant monkey frog, should be considered a psychedelic. The term psychedelic comes from Greek meaning “mind manifesting,” Nichols says. “You can imagine, it’s enhancing the properties of your mind, rather than just intoxicating you.” Other compounds such as stimulants and depressants modify the activity of the brain, but they don’t leave users with the kind of new insights and memorable experiences that come with psychedelics.