What exactly is in gas station weed?

National Geographic

2 days ago

Edibles containing the psychoactive compound delta-8-THC, derived from federally legal hemp, are available even in some U.S. states where cannabis remains banned—although they are not FDA-approved. Photographs by Rebecca Hale This article is part of The New Cannabis, a National Geographic exploration into the most critical questions raised by today's stronger, stranger, ever more accessible weed. Learn more.
Though the term is widely used in today's cannabis culture, synthetic marijuana is a bit of a misnomer. The truth is, 'there's no such thing as synthetic marijuana or synthetic cannabis,' says Deepak Cyril D'Souza, professor of psychiatry at the Yale School of Medicine and director of the Yale Center for the Science of Cannabis and Cannabinoids. Usually people use synthetic marijuana to refer to a cannabis product that was derived from hemp and contains the psychoactive substance delta-8, or one that was produced from a series of compounds that were synthetically made in a lab (aka synthetic cannabinoids).
While both types of products mimic the effects of THC, the primary psychoactive compound in marijuana, 'synthetic cannabinoids are between 10 and 200 times more potent' than the usual THC in cannabis, D'Souza says.
Yet many people don't realize this, and synthetic cannabinoids are very easy to purchase. They are often sold at gas stations, bodegas, convenience stores, and smoke shops around the United States. And because of a loophole in federal law, which makes delta-8-THC legal (unlike delta-9-THC, the primary psychoactive compound in cannabis), teenagers can buy gummies, flavored vaping cartridges, and other delta-8-containing products right off the shelf. (Delta-8 tends to be less potent than delta-9 but still carries risks on its own.) A study last year found that 11 percent of high school seniors reported using delta-8. This selection of cannabis edibles contains both delta-8-THC and delta-9-THC. Synthesized delta-8 also comes in other forms, including vapes, tinctures, and smokable hemp flower. How delta-8 products differ from regular marijuana
Delta-9 creates the high that people typically experience from consuming cannabis. Delta-8 has psychoactive effects that are similar to those produced by delta-9, though delta-8 is naturally less potent.
While delta-9 continues to be illegal at the federal level, delta-8 is legal because of a loophole in the U.S. Agriculture Improvement Act of 2018, which legalized the cultivation and sale of hemp.
Though hemp and marijuana both come from the Cannabis sativa plant, they differ in their chemical composition, especially their concentration of delta-9. By definition, hemp may not contain a delta-9 concentration of more than 0.3 percent on a dry weight basis, whereas marijuana can contain significantly more.
Hemp also contains small amounts of delta-8. To get enough delta-8 for commercial products, manufacturers extract and convert CBD (cannabidiol, another compound naturally present in cannabis that is legal and nonintoxicating) from hemp to delta-8 in a lab, using chemicals such as sulfuric acid, hydrochloric acid, toluene, or heptane.
Despite delta-8 being legal on a federal level, some states have banned or severely restricted it in recent years, which puts its legal status in a gray area. Even so, delta-8 remains legal in more states than not, as well as in Washington, D.C.
Unlike products that contain delta-9, delta-8 products are not regulated by the U.S. Food and Drug Administration, which means that potency and purity can vary. There's also a risk they may contain undetected impurities from the environment or the conversion process, research has found. In fact, common contaminants in delta-8 products include residual solvents, pesticides, microbes, and heavy metals like lead, arsenic, and mercury, all of which may pose their own health risks, according to studies.
Meanwhile, there was a significant uptick in concerned calls from consumers to America's Poison Centers about experiences with delta-8, with an 82 percent increase from 2021 to 2022 (to 3,358 calls).
Even without the presence of impurities, delta-8 can have problematic effects, especially because many people are consuming it in high amounts since they view it as 'weed lite' or 'marijuana lite,' experts say.
'A lot of young people think delta-8 is not as potent as delta-9,' notes Akhil Anand, an addiction psychiatrist and clinical assistant professor at the Cleveland Clinic. 'But because of the lack of regulations, the way it's consumed, and the risk of contaminants and adulterants … people can become dependent or addicted.' Edibles, like this chocolate bar containing delta-8 and delta-9, make up the third largest segment of the legal U.S. cannabis market, behind flower and vaping products. K2, spice, and skunk: 'off-the-charts intoxicating'
Unlike delta-8, synthetic cannabinoids are a class of substances that are made in a lab and designed to mimic THC from cannabis. 'It's not really cannabis at all,' Anand says, because synthetic cannabinoids are entirely manufactured from chemicals.
Some of these synthetic products—with names like K2, spice, Scooby snacks, or skunk—are marketed in colorful packaging as herbal incense or potpourri, and they're often made by spraying synthetic compounds (such as naphthoylindoles, naphthylmethylindoles, phenylacetylindoles, and others with equally tongue-twisting names) onto dried plant material so it looks like cannabis, Anand says.
These products are not legal—when it comes to their manufacturing, sale, or consumption—at the federal level or the state level. In fact, many of these compounds have been banned by the federal government and classified as Schedule I controlled substances by the Drug Enforcement Administration. In recent years there have been several arrests and indictments of people involved in synthetic cannabinoid drug trafficking rings, including arrests this year related to a website-driven scheme to provide K2 and spice to people in prisons.
Because standard drug tests are designed to detect traditional THC, they won't detect synthetic cannabinoids. Not surprisingly, these products often appeal to people who are concerned about being tested for drugs such as those in the military, the federal government, or the prison system, D'Souza says.
A complicating factor: 'We can't test for these in the emergency department,' Anand explains, 'so it becomes challenging to treat these patients because we don't know what they have taken.' And the patients can't or won't tell emergency department doctors what they have taken because 'they're often not in the right state of mind,' Anand says.
Consuming synthetic cannabinoids can be dangerous. One review of studies found these products were responsible for a 'higher toxicity than THC and longer-lasting effects,' including increased risk of psychiatric disorders. And deaths have been linked to synthetic cannabinoids laced with chemicals found in rat poison.
In a study in the July 2025 issue of the journal Drug and Alcohol Dependence, researchers analyzed adverse effects associated with the use of synthetic cannabinoids, as reported in 49 published studies. The predominant ones involved the neurological and cardiovascular systems, with symptoms such as seizures, altered consciousness, tachycardia (rapid heart rate), and hypertension. Another 2025 study found that people with a dependence on synthetic cannabinoids exhibited more impulsivity and self-harming behaviors than their healthy peers. These products are especially risky for teens because their brains are still developing, D'Souza adds.
'These can be off-the-charts intoxicating because manufacturers are putting high concentrations in these products,' says Robert Welch, a pharmacist and director of the National Center for Cannabis Research and Education at the University of Mississippi. 'My advice is just to avoid this stuff because there's no way to know what you're taking.'
Besides being dangerous in their own right, these synthetic products take attention 'away from the health benefits that properly grown and sourced cannabis products can have,' Welch says. 'People don't understand the differences.' A version of this story appears in the September 2025 issue of National Geographic magazine.