Roughly 64 million Americans aged 12 or older used marijuana in the past year, making it by far the most common illicit drug in the country. Beyond marijuana, tens of millions more misused prescription medications, used stimulants, or took hallucinogens. The numbers come from SAMHSA’s 2024 National Survey on Drug Use and Health, the largest annual survey tracking substance use across the United States.
The Biggest Numbers at a Glance
Marijuana dominates the picture. In 2024, 22.3% of people aged 12 or older, or about 64.2 million people, reported using it in the past year. That’s nearly one in four Americans above the age of 11. Past-month use is lower but still substantial: the CDC estimates about 52.5 million Americans used cannabis at least once in a recent year, and a significant share use it regularly.
After marijuana, the next most commonly used substances are hallucinogens (10.4 million people, or 3.6%), opioids including heroin and misused prescription painkillers (7.8 million, or 2.7%), cocaine (5.0 million, or 1.8%), and methamphetamine (2.6 million, or 0.9%). These categories overlap, since many people use more than one substance.
Federal surveys define “illicit drugs” broadly. The category includes marijuana, cocaine, heroin, hallucinogens, inhalants, methamphetamine, and any misuse of prescription painkillers, tranquilizers, stimulants, or sedatives. It does not include alcohol or tobacco, which have their own massive usage numbers.
Opioids and the Fentanyl Crisis
About 7.8 million Americans misused opioids in the past year, either through heroin use or by taking prescription painkillers in ways other than prescribed. Within that group, roughly 5.7 million had a diagnosable opioid use disorder in 2023, meaning their use had progressed to a point where it caused significant problems in their daily lives and they struggled to stop.
Fentanyl has reshaped the risk landscape dramatically. Provisional CDC data for the 12-month period ending in June 2025 counted 39,261 overdose deaths involving fentanyl alone. The drug is now present in a wide range of street supplies, from counterfeit pills sold as prescription opioids to cocaine and methamphetamine that users may not realize has been contaminated.
Stimulant Use Is Climbing
Cocaine and methamphetamine together account for about 7.6 million past-year users. Cocaine use sits at 1.8% of the population aged 12 and older, while methamphetamine use is about half that at 0.9%. These percentages sound small, but they translate to millions of people, and stimulant-related harms have been rising alongside the opioid crisis as fentanyl increasingly contaminates stimulant supplies.
Workplace drug testing data tells a parallel story. Quest Diagnostics, which processes millions of employee drug tests annually, reported that amphetamine positivity in the general workforce climbed to 1.7% in 2024, up from 1.5% the year before. That trend has been moving upward for several years.
What Drug Testing Reveals About the Workforce
The overall positivity rate for workplace urine drug tests was 4.4% in 2024, a slight dip from 4.6% the year before. Marijuana remains the most frequently detected substance at 4.5% positivity in the general workforce. Cocaine positivity held steady at 0.24%.
The more telling numbers come from targeted testing. When employers ordered “for-cause” tests, meaning they had reason to suspect an employee was impaired, 33.1% came back positive. Post-accident testing showed a 10.2% positivity rate. Among federally mandated safety-sensitive workers like truck drivers and airline employees, positivity rates were lower across the board but still present: 4.5% after accidents and 12.6% on for-cause tests.
Fentanyl showed one of the starkest patterns. In random workplace tests, fentanyl positivity was 1.13%, but in pre-employment screenings it was only 0.14%. That 707% gap suggests that people using fentanyl are far more likely to be detected through random testing than to be screened out before hiring.
Most People Who Need Treatment Don’t Get It
The gap between the number of Americans who have a substance use disorder and those who actually receive professional help is enormous. In one well-cited estimate, 20.3 million people needed treatment for a substance use disorder but only 3.7 million received it. That means roughly 82% of people who needed help went without.
The reasons are layered. Cost and lack of insurance remain barriers for many, but stigma, limited availability of treatment programs (especially in rural areas), and long wait times for facilities all play a role. For opioid use disorder specifically, effective medications exist that reduce cravings and prevent overdose, yet only a fraction of the 5.7 million people with the disorder receive them.
Putting the Numbers in Context
When people ask “how many Americans do drugs,” the answer depends heavily on what counts. If you include any illicit substance use in the past year, including a single instance of marijuana use in a state where it’s legal, tens of millions of Americans qualify. If you narrow the question to people with a substance use disorder whose drug use is causing real harm, the number is closer to 20 million. And if you focus on the hardest-hit populations, those using opioids, methamphetamine, or fentanyl regularly, you’re looking at roughly 8 to 10 million people whose health and lives are at serious risk.
The legal landscape matters too. As more states have legalized recreational marijuana, the line between “illicit” and “legal” drug use has blurred. A 22-year-old buying cannabis from a licensed dispensary in Colorado and a person injecting heroin in a city park both show up in the same federal survey data, even though the risks, legal consequences, and social contexts are vastly different. The 64.2 million figure for marijuana use includes both scenarios, which is worth keeping in mind when interpreting the headline numbers.