They're sold in gas stations, vape shops, online and in other stores around the country in seemingly countless enticing forms: gummies, chocolate bars, chips. Their packaging lists things like delta-8 THC, micro- and macrodoses of “psychedelics” and “nootropics."

These substances are often sold through legal loopholes, despite concerns about potential health risks and a lack of oversight of how they're produced. And in the absence of federal rules, many states have banned or have tried to ban delta-8 THC.

Legal but under-regulated drugs are easy to come by, but experts say there are still a lot of uncertainties. Here's what to know.

How are these substances legal?

Drug laws are often specific to the substance, so federal and state regulators are left chasing the newest chemical concoction.

Delta-8 THC exploded in popularity under the Agriculture Improvement Act of 2018, more commonly known as the Farm Bill. Under that law, hemp products and the cannabinoids that could be made from them were classified as distinct from marijuana.

Delta-8 has just a slight chemical tweak from the psychoactive delta-9 compound found in marijuana, but it can still get you high.

It remains in a legally ambiguous area with restrictions that vary state by state, said Robert Mikos, a marijuana policy and law expert at Vanderbilt University. Substances like cannabinoids are also easy to change into new but similar versions of drugs that may come under scrutiny.

“There’s been all sorts of things that (have) cycled through popularity over time,” he said. “And government enforcement is always one step behind what the chemists can come up with.”

If it's on a store shelf though, it's safe, right?

Not necessarily.

Because of a lack of oversight into manufacturing processes and a lack of uniform labeling requirements, it's hard to know what exactly is in a particular product.

For example, the U.S. Food and Drug Administration began investigating illnesses earlier this year caused by recalled Diamond Shruumz products, which in addition to containing muscimol, a legal psychoactive compound from the Amanita muscaria mushroom, were found to contain other unlisted ingredients, including psilocin, a controlled substance.

It’s hard to even know basic information about what the potency of the drug in many of these products is, said Dr. Ginger Nicol, who leads the psychedelics research program at Washington University in St. Louis.

And the concern isn't just limited to the drugs themselves: It extends to other things that could be introduced in the manufacturing process, said Dr. Igor Grant, director of the University of California, San Diego's Center for Medicinal Cannabis Research.

He pointed to how delta-8 is made from CBD.

The chemical process to make delta-8 uses strong acids and more, Grant said, and if some of those other trace chemicals are left behind, they can pose added health risks to those already posed by delta-8 itself.

“If this was done by the Food and Drug Administration's standards where they have strong regulations about purity and all that, it'd probably be fine," he said. "But that's not how it's made.”

What should you do?

Nicol suggested that people to talk to their doctor before taking anything, especially if it’s an unregulated drug.

That's in part because of the lack of rigorous research that could better understand the drugs' effects, side effects and safety — and in part because there is so little oversight.

“You can get a bad batch,” she said. “Nobody is necessarily testing it for purity or contamination.”

___

The Associated Press Health and Science Department receives support from the Robert Wood Johnson Foundation. The AP is solely responsible for all content.