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Is cannabis safe after 65? Stanford experts reveal 5 risks older adults should know

Date:

May 15, 2026

Source:

Stanford Medicine

Summary:

Cannabis use among older adults is rising fast, but today’s marijuana is far more potent than many people realize — and experts warn the risks may be underestimated. Stanford Medicine specialists say modern cannabis can increase the chances of heart problems, falls, memory issues, dangerous drug interactions, and even addiction, especially for people over 65.

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Modern cannabis may help some older adults cope with pain and illness — but experts warn its hidden risks are growing just as fast as its popularity. Credit: Shutterstock

As cannabis use grows among older Americans, Stanford Medicine experts are warning that today's marijuana products are far more powerful than many people realize, and they may come with significant health risks.

Eloise Theisen never expected to become a specialist in medical cannabis. Now a geriatric nurse practitioner focused on cannabis therapy at Stanford Medicine, she first turned to cannabis herself after a severe car accident left her with chronic pain that other treatments failed to relieve.

When she later returned to work in an oncology clinic, she noticed many patients were already using cannabis or considering it, often without guidance from medical professionals.

"I found that our patients were going to use it whether their providers approved of it or not," Theisen said. "Many of our patients were older, and they had risks that needed to be evaluated and addressed before they started using cannabis."

Cannabis Use Is Rising Among Older Adults

Both medical and recreational cannabis use continue to increase across the United States, including among adults over 65. Yet researchers still have major unanswered questions about how cannabis affects the body and brain, partly because marijuana remains federally illegal, making some kinds of research difficult.

Many older adults use cannabis in hopes of easing chronic pain, insomnia, or anxiety. However, Smita Das, MD, PhD, clinical associate professor of psychiatry and behavioral sciences at Stanford Medicine, said there is still no broad medical agreement that cannabis effectively treats these conditions.

Experts say older adults face unique risks from regular cannabis use. These include higher chances of heart disease, certain cancers, addiction, cognitive problems, and dangerous medication interactions. Today's cannabis products are also much stronger than the marijuana many people encountered decades ago, increasing the risk of accidental overuse.

Stanford Medicine specialists shared five important things older adults should know before using cannabis.

1. Today's Cannabis Is Much Stronger Than It Used To Be

Medical marijuana is legal in 40 states and the District of Columbia, while recreational cannabis is legal in 24 states and D.C. Although regular use among seniors remains relatively uncommon, it is rising quickly. According to the National Survey on Drug Use and Health, 7% of adults over 65 reported recent cannabis use in 2023, compared with less than 5% in 2021.

Many older adults may not realize how dramatically cannabis potency has changed. In the 1970s, marijuana typically contained between 1% and 4% tetrahydrocannabinol (THC), the compound responsible for the drug's psychoactive effects. Today, legal cannabis flower averages around 20% THC, and some strains contain as much as 35%.

Other cannabis products can be even more concentrated. Oils, edibles, and concentrates may contain THC levels approaching 90%. Synthetic marijuana products such as spice or K2 are even stronger and have been linked to heart problems. These products are illegal in California and many other states.

"We're trying to catch up in our understanding of how that drastic of an increase in the psychoactive ingredient is impacting the brain and the body," said Claudia Padula, PhD, assistant professor of psychiatry and behavioral sciences.

The increased strength of cannabis products may also help explain a rise in accidental overconsumption among older adults. A Canadian study comparing emergency room visits before and after nationwide legalization found that cannabis poisoning cases among adults over 65 nearly tripled.

"There are so many different formulations and so many different strengths," Das said. "This is really not the cannabis of the '70s."

2. Cannabis May Raise Risks for Heart Disease and Cognitive Problems

Although cannabis research is still developing, several studies have linked regular cannabis use to cardiovascular disease.

Joseph Wu, MD, PhD, director of the Stanford Cardiovascular Institute and the Simon H. Stertzer, MD, Professor of Medicine & Radiology, said this is especially concerning for older adults because heart disease remains the leading cause of death in the