Cannabis Risks And Product Liability

Although cannabis research has been outpaced by consumer behavior and public policy, the research is catching up. A growing body of medical studies link cannabis exposure to cardiovascular harms that can include heart attack, stroke, heart failure, arrhythmia, and blood vessel dysfunction. These findings span the different methods of cannabis consumption and appear to affect certain groups more than others, though cardiovascular injury has been documented in otherwise healthy adults who use high-THC cannabis products.

Modern cannabis products often contain far higher levels of THC than documented in past studies. Today, these products may also include certain intoxicating hemp products. This higher potency is concerning for possible increased cardiovascular and other health risks, particularly with daily or near-daily use.

This article summarizes recent evidence, highlights those who may be most at risk, and addresses key product liability considerations for cardiovascular risks from high-THC products. The cannabis and hemp industry is not prepared for these evolving product liability risks and must shift its focus now or find itself faced with large future jury verdicts.

How THC Impacts Cardiovascular Risk

THC interacts with the endocannabinoid system throughout the body, including within the cardiovascular system. Acute effects can include increased heart rate and blood pressure, particularly for high-THC products and regardless of the method of ingestion.

The ratio of THC to CBD may be an important but underappreciated factor in determining whether a specific cannabis product has the potential for cardiovascular harm. THC is known to stimulate the sympathetic nervous system while inhibiting the parasympathetic nervous system, though it can have varying effects at different doses. In contrast to THC, CBD can reduce heart rate and blood pressure, while improving vasodilation and reducing inflammation. The specific effect of CBD is again dose-dependent.

What Recent Studies Say about Cardiovascular Risks

Recent findings have established connections between cannabis use and heart attack, stroke, arrhythmia, and other serious cardiovascular conditions. A 2025 review of multiple studies reported increased risks for acute coronary syndrome and stroke, and a more than doubled risk of cardiovascular death among cannabis users. Another large study funded by the National Institutes of Health (NIH) and published in 2024 concluded that cannabis use, especially daily use, is associated with higher odds of heart attack and stroke, with a dose-response pattern (i.e., higher odds with more days used per month). Daily users had 25% higher odds of heart attack and 42% higher odds of stroke versus nonusers.

Regarding heart failure, a recent study presented to the American Heart Association (AHA) reported that daily cannabis users had about a 34% higher risk than nonusers of developing heart failure over approximately four years, partly due to coronary artery disease.

Other recent review and observational data have associated cannabis use with atrial fibrillation and ventricular arrhythmias in some users. Case reports have also described severe rhythm disturbances temporally linked to cannabis use.

There is also evidence of a link between cannabis use and broader vascular implications. In a review of national inpatient data from 2016 through 2019, marijuana users were more than three times as likely to have a diagnosis of peripheral artery disease as nonusers. Similarly, a large 2025 study found that chronic cannabis smokers and edible THC users had clinical markers of blood vessel dysfunction compared with nonusers.

Who May Be at Greater Risk?

The data suggests that cannabis use may disproportionately impact certain vulnerable groups including adolescents and young adults, older adults, those taking multiple medications, and pregnant women.

Near-daily cannabis use is common among 18- to 25-year-olds. These patterns are associated with heavier THC exposure and cannabis use disorder. Young men also feature prominently in emergency department visits in legalized states with cardiovascular complaints including heart attack.

Older adults may also be at an increased risk. Cannabis use has been linked to a 20% higher chance of major adverse cardiac and cerebrovascular events in hospitalized adults over age 65 with diabetes, hypertension, or hyperlipidemia.

Cannabinoids have the potential for significant adverse drug interactions, including with various cardiac medications such as beta-blockers, statins, and protease inhibitors.

THC crosses the placenta and may affect fetal development. Although definitive data on cardiovascular outcomes are limited, authoritative bodies recommend avoiding cannabis during pregnancy and lactation.

Product Liability Considerations

As evidence of cardiovascular risks accumulates, cannabis and hemp companies face the same core product liability frameworks that govern other consumer products. Manufacturers, distributors, and retailers have a duty to warn about risks that are known or knowable in light of generally accepted scientific knowledge at the time of sale. They are "held to the knowledge and skill of an expert in the field" and should keep abreast of emerging science. See, e.g., Carlin v. Superior Court, 13 Cal.4th 1104, 1113 (Cal. 1996).

Cannabis and hemp companies should adopt evidence-based warnings and update them as research evolves. Those warnings may comprise method-of-use differences such as delayed onset with edibles, high-THC potency warnings, impairment warnings, and risk disclosures regarding potential increased harm to vulnerable customer populations. In addition to cardiovascular risks, cannabis-related health warnings may include cannabis use disorder, cannabis-induced psychosis, hyperemesis, and adverse drug interactions.

Aside from failure to warn, cannabis and hemp companies must prepare to defend themselves from future prospective plaintiffs who will argue that the design of cannabis vape and edible products make those products unreasonably dangerous based on high-THC formulations, misleading potency messaging, or designs that encourage overconsumption. As mentioned, the industry is not prepared and must shift its focus now or find itself faced with large future jury verdicts.

Insurance Industry Recognition and Response

Insurers should take notice of these evolving product risks. Forms and underwriting procedures should be reviewed regularly to ensure that they adequately reflect the current underwriting intent for insureds that manufacture, distribute, or sell cannabis or hemp products. Due to the quickly evolving nature of cannabis research, some insurers certainly have risk on the books that were not intended to be covered.

Of the various product liability policies on the market that are tailored to cannabis and hemp risks, some contain strict health hazard exclusions, some do not, and a few attempt to forge a middle ground approach by covering "acute" health injuries but excluding chronic harm or long-term effects. Cardiovascular injuries often do not fall neatly into these categories and may require expensive medical causation discovery to sort out whether an injury is caused by an acute or longstanding process. Policy definitions, endorsements, exclusions, and application questions should therefore be revisited and updated as needed.

Conclusion

Cannabis does not have the same harm potential as tobacco or alcohol, but neither is it entirely benign. Many in the cannabis and hemp industries have quickly embraced new evidence of the benefits of cannabinoids while largely overlooking studies that raise potential health concerns. There is an understandable urge to believe that cannabis cannot be harmful because it is a plant and therefore "natural." Such "positive" messaging, amplified by the media, politicians, and celebrities, has normalized cannabis use to the delight of millions of Americans. This exuberance, however, should be tempered with a balanced view rooted in the current evidence.

It is important to emphasize that most of the data on cardiovascular harm discussed above are observational and subject to confounding from factors such as the underreported co-use of other substances. Associations do not prove causation. Nonetheless, multiple independent datasets, dose-response patterns, and consistency across populations have strengthened the inference that cannabis poses cardiovascular risks, especially from frequent high-THC use and inhaled smoke. Cardiologists are calling for large prospective studies to refine estimates and guide policy. Clinicians are meanwhile being urged to more proactively screen their patients for cannabis exposure, including in younger patients with cardiac symptoms.

As the evidence base grows, regulators, clinicians, companies, and consumers share responsibility for reducing harm. This may include funding prospective studies, integrating cardiovascular risk into clinical care, and implementing clear, accurate product warnings. Until more definitive data are available, prudence is warranted—particularly for youth, pregnant individuals, older adults, and anyone with or at risk for heart disease.

Originally Published by CLM Magazine

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