It’s known by the street name “gas station heroin,” but a new government report finds the highly addictive supplement Neptune’s Fix may also contain synthetic pot.

The product has already been linked to seizures, brain swelling and hallucinations, researchers reported Thursday in Morbidity and Mortality Weekly Report, a publication of the U.S. Centers for Disease Control and Prevention.

The CDC report centered on a 2023 investigation of 17 adults in New Jersey who had severe reactions after consuming Neptune’s Fix or similar products containing tianeptine. Thirteen were hospitalized in intensive care as a result.

Tianeptine, an antidepressant that can act like an opioid, is sold as a dietary supplement at gas stations and convenience stores across the United States. It’s often marketed for pain relief, depression or anxiety. While not approved for use in the United States, it is approved for use in some European, Asian and Latin American countries. 

In the CDC study, doctors in New Jersey tested six samples of Neptune’s Fix consumed by two of the patients. They discovered the presence of more than tianeptine: kavain, a substance used for anxiety, and two different types of synthetic pot were also detected in the test samples. 

“It was a surprise to find those compounds in there at all,” senior study author Dr. Diane Calello, medical director of the New Jersey Poison Control Center, told NBC News. “That’s probably not what the people who bought those products were looking for.”

She said it is not yet clear whether all 17 patients, who ranged in age from 28 to 69, were exposed to the synthetic pot, which can cause seizures and coma.

Several of the patients did experience high blood pressure and seizures, as well as irregular or rapid heartbeats, and at least one patient suffered a heart attack. Among the 13 admitted to the ICU, seven had to be intubated. No one died.

Dr. Pieter Cohen, an associate professor at Harvard Medical School who studies the regulation of supplements, told NBC News that the reported symptoms sounded “dramatic and alarming.”

“Usually we might see something like this in 1 in 100 poisonings,” he said. “That’s potentially an incredibly potent mixture of drugs.”

The U.S. Food and Drug Administration first warned consumers not to buy or use Neptune’s Fix in November, noting that the products could contain other harmful ingredients. 

In January, the maker of Neptune’s Fix agreed to voluntarily recall its products, which include Neptune’s Fix Elixir, Neptune’s Fix Extra Strength Elixir and Neptune’s Fix Tablets.

Cohen said there needs to be more regulation of supplements in the United States, noting that the FDA’s current power is “very limited.” 

“Consumers remain at risk when they consume dietary supplements here in the United States,” he stressed.

More information

Visit the U.S. Drug Enforcement Administration has more on tianeptine.

SOURCE: Morbidity and Mortality Weekly Report, Feb. 1, 2024; NBC News