Reports of fentanyl-laced marijuana have ranged from the appearance of credibility to the obviously incredible. For example, Spectrum News in New York warned its readers of “marijuana laced with fentanyl” and included several Monroe County Sheriff’s Office employees who reported, not coming into contact with but suspecting synthetic marijuana laced with fentanyl was being sold in New York State.[i] The report ended with a reminder to buy legal marijuana from New York State’s burgeoning marijuana legalization program.[ii] And a district attorney in Montgomery County, Pennsylvania, claimed in February 2023 to have detected fentanyl in THC gummies, but days later retracted that assertion noting that the gummies “did not alert to any illegal drugs at the lab’s threshold level of detection.”[iii] There are countless reports like this, where marijuana is suspected to be laced with fentanyl, but later scientifically determined not to contain fentanyl. To date, the United States Drug Enforcement Administration has yet to report seizing or otherwise discovering fentanyl-laced marijuana.


But could someone lace marijuana with fentanyl? Sure. But there is an additional problem to this proposition. Dr. Ryan Marino has pointed out that fentanyl decomposes at temperatures less than 1/6th that of a flame. Meaning, if marijuana were laced with fentanyl, it would be completely decomposed the moment the marijuana was lit with a lighter. While it is possible to smoke (vaporize) fentanyl, adding fentanyl to THC that was going to be vaped would cause the loss of most of both the fentanyl and THC. Lacing marijuana with fentanyl also just makes little sense. Some argue that dealers would want to lace marijuana with fentanyl to “hook” people who smoke marijuana on fentanyl. But this overlooks two critical points: lacing marijuana with fentanyl would be costly and would be counter to the market for marijuana (meaning, the population who seeks marijuana is unlikely to be the same population seeking fentanyl.)

In any event, while anecdotal evidence exists (every seems to know someone who knows someone who got fentanyl laced marijuana), there has yet to be a single confirmed laboratory case of marijuana testing positive for fentanyl.


[i] See Wendy Wright’s “New York Law Enforcement Officials Issue Warning for Illegally Purchased Marijuana Laced with Fentanyl,” Spectrum News, published May 24, 2023, online at–law-enforcement-officials-issue-warning-for-illegally-purchased-marijuana-laced-with-fentanyl. “I’ve known it to be on the synthetic, I have not known it to be on the marijuana in our specific area. But that really means nothing when they’re being packaged by, in some references, just criminals,” Genier said of hearing of reports of marijuana being laced with fentanyl. 


[ii] “To bolster the public health and safety of all New Yorkers, we are providing them with information they need to make informed decisions and enjoy cannabis responsibly,” Hochul said in a statement last month. “As we continue to build a healthier and more equitable cannabis market, I am proud to launch this important public education campaign to promote safer, legal purchases of cannabis from licensed dispensaries throughout our state.”


[iii] V. Fiorillo, “OK, So Maybe Those Gummies Didn’t Contain Heroin or Fentanly After All,” at, published February 28, 2023.