In 2022, the federal government reported that, in samples seized by the Drug Enforcement Administration, average levels of tetrahydrocannabinol, or THC—the psychoactive compound in weed that makes you feel high—had more than tripled compared with 25 years earlier, from 5 to 16 percent. That may understate how strong weed has gotten. Walk into any dispensary in the country, legal or not, and you’ll be hard-pressed to find a single product advertising such a low THC level. Most strains claim to be at least 20 to 30 percent THC by weight; concentrated weed products designed for vaping can be labeled as up to 90 percent.