CBD-Based Drug Shows No Heart Safety Risks in Patients With CVD or Risk Factors

An oral, pharmaceutical-grade cannabidiol (CBD) solution was well tolerated and showed no concerning effects on heart rhythm or overall safety in patients with a history of heart disease or major cardiovascular risk factors, according to findings presented at the European Society of Cardiology (ESC) Heart Failure Congress 2025.¹

The randomized, double-blind trial evaluated a pharmaceutically manufactured, good manufacturing practice (GMP)–grade CBD drug in 89 adults with a history of cardiovascular disease (CVD) or at least 1 major CVD risk factor who were hospitalized with noncritical COVID-19.² Participants received either oral CBD titrated up to 7.5 mg/kg twice daily or placebo for 28 days, followed by a safety evaluation through day 60.

“We knew that patients with CVD or CVD risk factors who were hospitalised for COVID-19 infection may be at high risk of cardiac inflammation,” said Leslie T. Cooper Jr, MD, general cardiologist and chair of the department of cardiovascular medicine at Mayo Clinic in Florida, explaining the rationale for the study. “The pandemic ended before we had recruited sufficient participants to analyse whether GMP-cannabidiol had a positive effect on the primary efficacy endpoint but we thought that the lack of safety signals was important data to share.”

Researchers observed no significant difference in adverse events (AEs) or serious AEs (SAEs) between the 2 groups. Among those receiving GMP-CBD, 24.4% experienced treatment-related AEs compared with 22.7% in the placebo group; serious AEs occurred in 11.1% of the treatment group and 9.1% of the placebo group. No deaths occurred in the CBD group, while 2 deaths due to respiratory failure occurred in the placebo group.

The most common AEs included gastrointestinal symptoms (22.2% with CBD vs 20.5% with placebo), nervous system disorders (17.8% vs 18.2%), and respiratory symptoms (11.1% vs 9.1%), all showing no statistically significant differences between groups. Four patients in each group experienced cardiac disorders, and electrocardiogram monitoring revealed a single instance of mild QTc prolongation in 1 patient receiving CBD. However, overall mean QTc values slightly decreased in the CBD group from 425 msec to 418 msec, and minimally increased from 418 msec to 419 msec in the placebo group, indicating no clinically relevant change.

Researchers observed no significant safety difference between the CBD and placebo groups. | Image credit: Irina_Evva – stock.adobe.com

CBD for CVD

CBD is a nonpsychotropic compound derived from cannabis.³ It has been shown in preclinical studies to reduce cardiac inflammation by modulating the NLRP3 inflammasome pathway, which is implicated in myocarditis, pericarditis, and heart failure.^1,3 As of May 2025, Epidiolex (Jazz Pharmaceuticals) is the only cannabis-derived product approved by the FDA, indicated to treat seizures associated with Lennox Gastaut syndrome, Dravet syndrome, or tuberous sclerosis complex.⁴

“FDA is aware that unapproved cannabis or cannabis-derived products are being used for the treatment of a number of medical conditions including, for example, AIDS wasting, epilepsy, neuropathic pain, spasticity associated with multiple sclerosis, and cancer and chemotherapy-induced nausea,” the FDA said last year with regard to regulating cannabis and cannabis-derived products. “To date, FDA has not approved a marketing application for cannabis for the treatment of any disease or condition and thus has not determined that cannabis is safe and effective for any particular disease or condition. The agency has, however, approved one cannabis-derived and three cannabis-related drug products.”

While the current study did not assess efficacy, its favorable safety profile offers hope as the cardiology field awaits the results of 2 larger ongoing trials.¹ The phase 2 ARCHER trial (NCT05180240) is evaluating GMP-CBD in patients with acute myocarditis, with results expected later in 2025; the phase 3 MAVERIC trial (NCT06708299) will assess the compound in patients with recurrent pericarditis, with results anticipated in 2026.

It’s important to note that the trial was stopped early due to low enrollment, and its double-digit sample size limits researchers’ ability to detect less common AEs or draw strong conclusions on safety. Participants were also followed for only 60 days, making it difficult to assess long-term cardiac safety, and because the study focused solely on safety in a specific population, these results may not be generalizable to broader patient groups. While no major safety concerns were observed, larger and longer-term trials are needed to fully understand the risks and potential benefits of CBD-based therapies in cardiovascular care.

References

1. Cooper L, Mcnamara DM, Bhimaraj A, et al. Cardiac safety of pharmaceutically manufactured cannabidiol in patients at increased cardiovascular risk. Presented at: ESC Heart Failure Congress 2025; May 17, 2025; Belgrade, Serbia.
2. No cardiac safety concerns reported with a pharmaceutically manufactured cannabidiol formulation. European Society of Cardiology. May 17, 2025. Accessed May 21, 2025. https://www.escardio.org/The-ESC/Press-Office/Press-releases/No-cardiac-safety-concerns-reported-with-a-pharmaceutically-manufactured-cannabidiol-formulation
3. Martinez Naya N, Kelly J, Corna G, Golino M, Abbate A, Toldo S. Molecular and cellular mechanisms of action of cannabidiol. Molecules. 2023;28(16):5980. doi:10.3390/molecules28165980
4. FDA regulation of cannabis and cannabis-derived products, including cannabidiol (CBD). FDA. Updated July 16, 2024. Accessed May 21, 2025. https://www.fda.gov/news-events/public-health-focus/fda-regulation-cannabis-and-cannabis-derived-products-including-cannabidiol-cbd