A lawsuit, filed on behalf of more than 40 plaintiffs, claims that cannabis companies did not warn them of mental health risks when purchasing from legal retail stores. The lawsuit states, “This class action lawsuit seeks to hold Cresco Labs, Green Thumb, Verano Holdings, and Verano LLC responsible for promoting their cannabis products to recreational users as safe and appropriate for widespread use despite scientific evidence to the contrary.”

The lawsuit also states, “Cannabis purveyors market and promote their cannabis products to an unsuspecting public through a public relations megaphone as the antidote to ailments of all kinds, including, among others, insomnia, narcolepsy, over-eating, cancer, auto-immune disorders, neuropathy, pain, anger, boredom, sadness, shyness, irritable bowel syndrome, grief, and opioid addiction. These claims are part of a calculated strategy in which the cannabis industry, including Defendants Cresco Labs, Green Thumb, Verano Holdings, and Verano LLC, have unleashed an acute intoxicant—tetrahydrocannabinol (“THC”)—at unprecedently [sic] high concentrations on its customers.”

In addition, the suit claims that these companies “have known at all relevant times that their cannabis products have not been approved as a treatment for a single medical disorder by the Food and Drug Administration (“FDA”) and that no credible scientific research has established that cannabis is safe and effective in treating mental health or other health disorders in the manner they claim. A 2025 narrative review and meta-analysis published in the Journal of the American Medical Association of 124 recent randomized controlled trials found that the evidence that cannabis “treats” disorders such as pain, anxiety, post-traumatic stress disorder (“PTSD”), insomnia, and most other hyped uses is weak or non-existent…In fact, contrary to Cresco Labs, Green Thumb Verano Holdings, and Verano LLC’s public claims about the purported health benefits of their products, and as they knew or should have known, medical research demonstrates that the use of cannabis causes and exacerbates the development of schizophrenia, psychosis,1 bipolar disorder, suicidal ideation, depression, and anxiety,2 and other serious health disorders, including adverse cardiovascular events, cannabis hyperemesis syndrome, and cannabis use disorder; it also poses significant risks to fetuses and children from prenatal exposure. Cresco Labs, Green Thumb, Verano Holdings, and Verano LLC also knew or should have known that cannabis was not a safe or effective medicine or therapy for mental health disorders or many other medical conditions identified by Defendants but in fact makes symptoms worse, as shown by a large body of credible scientific research.”

The suit claims that “Cannabis is not the medicine as Cresco Labs, Green Thumb, Verano Holdings, and Verano LLC claim that it is, least of all medicine for mental health disorders; and Cannabis is and has always been a dangerous drug that requires sufficiently clear and adequate warnings for informed use.”

The suit was filed in federal court in the Northern District of Illinois, as well as in Madison County. Other states listed in the suit include Arizona, Connecticut, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Jersey, New York, Ohio, Rhode Island, and Virginia.

The lawsuit argues that the existing labeling laws in Illinois, which require the following warning, is not enough: “Smoking is hazardous to your health. This product contains cannabis and is intended for use by adults 21 and over. Its use can impair cognition and may be habit-forming. This product should not be used by pregnant or breastfeeding women. It is unlawful to sell or provide this item to any individual, and it may not be transported outside the State of Illinois. It is illegal to operate a motor vehicle while under the influence of cannabis. Possession or use of this product may carry significant legal penalties in some jurisdictions and under federal law.”

The Cannabis Regulation and Tax Act and Compassionate Use of Medical Cannabis Program Act already have long lists of labeling and warning requirements. The litigation was filed by several attorneys, including former McHenry County State’s Attorney Patrick Kenneally. Kenneally, who was a prosecutor in 2023, demanded that cannabis dispensaries in McHenry County post warnings about the potential harms of cannabis or he would file a consumer fraud lawsuit. Kenneally now works for Burke Law Group in Chicago, a private practice.

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