Medical Marijuana and POTS: Does Cannabis Help or Hurt?

Has Cannabis Been Studied in POTS?

It hasn't. Our team searched PubMed for POTS together with cannabis, cannabinoids, cannabidiol and marijuana, and the only record was a withdrawn paper on an unrelated question. So nobody can tell you from a study that cannabis helps POTS or harms it. What can be said comes from 3 places: studies of what THC does to the circulation in people without POTS, trials of medical cannabis for pain and sleep, and what our team notices in patients who already use it.

What Does THC Do to Heart Rate and Blood Pressure?

THC pushes on the same controls that POTS strains. A review of marijuana's cardiovascular effects found that marijuana and THC increase heart rate, slightly increase blood pressure lying down, and on occasion produce marked orthostatic hypotension, a drop in blood pressure on standing (Jones, 2002). In 3 men given THC by inhalation, the blood pressure drop on standing came from the veins widening, and it eased when they lay back down (Merritt, 1982).

The study closest to the POTS question measured blood flow to the brain. 10 healthy men stood up after smoking either marijuana or a placebo cigarette while a Doppler probe recorded blood velocity in the middle cerebral artery. 6 of the 10 reported moderate to severe dizziness on standing after marijuana, and none did after placebo. The men with severe dizziness had marked falls in both blood pressure and brain blood velocity. The men with moderate dizziness had a fall in brain blood velocity with their blood pressure holding (Mathew, 1992).

After placebo After marijuana

The authors concluded that the dizziness may come from low blood pressure and from the brain losing its ability to hold its own blood flow steady (Mathew, 1992). That matters for how our team thinks about POTS. In our view the fast heart rate on standing is a compensation that protects blood flow to the brain, and it's working. A drug that widens the veins and lowers brain blood velocity when a healthy person stands is pushing against that compensation. Nobody has measured whether it does the same in POTS, so that's our team's reading of the mechanism.

Does Weed Make POTS Worse Over Time?

The first effects fade with regular use. Tolerance to most of the early cardiovascular effects appears rapidly, and with repeated exposure the standing blood pressure drop disappears, blood volume increases and heart rate slows (Jones, 2002). That was described in users without POTS, and it means the first few uses are when the standing symptoms are most likely.

Dizziness moves the other way in the trials. In a meta-analysis of randomized trials of medical cannabis for chronic pain, the added risk of dizziness over placebo was 9% in trials shorter than 3 months and 28% in trials of 3 months or longer (Wang, 2021). A second meta-analysis, of cannabis for impaired sleep, put the added risk of dizziness at 29% in the longer trials (AminiLari, 2022). For someone whose main symptom is already dizziness on standing, that's the number to weigh.

What Does Cannabis Help With?

Our team sees it used as a palliative, something that eases symptoms without changing what causes them. 2 uses come up most.

Pain. The evidence is best here. A systematic review found moderate-quality evidence supporting cannabinoids for chronic pain (Whiting, 2015), and the later meta-analysis put a size on it: non-inhaled medical cannabis probably gives about 10% more people a noticeable reduction in pain than placebo does (Wang, 2021). For hypermobility, which often travels with POTS, the evidence is a single case (Dar, 2021) and an uncontrolled registry of 161 people in which pain scores improved and 31% reported at least 1 adverse event (Dickinson, 2025). Without a comparison group, a registry can't separate the drug from everything else.

Falling asleep. Our team has seen it help some people get to sleep, and that's an observation from the exam room. The trials are less generous. Medical cannabis may improve impaired sleep in people with chronic pain, with a benefit that's likely small (AminiLari, 2022), and a review of sleep recordings found that cannabis doesn't consistently change how long it takes to fall asleep, how long people sleep, or the stages of sleep. Withdrawal after regular use was consistently tied to shorter sleep and a longer time to fall asleep (Velzeboer, 2025). Why sleep matters for recovery is covered in sleep and neuroplasticity in POTS.

What Are the Downsides?

The first is the standing dizziness described above. The second is what regular use does to thinking. In a cohort followed from childhood to midlife, persistent cannabis use was associated with a decline across areas of thinking, and stopping didn't fully restore function in people who had started as adolescents (Meier, 2012). That study followed people who began young, so it doesn't settle the question for an adult who starts at 35.

Our team's concern sits in the same place. Getting better from POTS depends on the brain relearning how to regulate blood flow, heart rate and balance, and in our view anything that dulls brain function over years works against that. Like any palliative, cannabis has a ceiling: it can make a hard night or a painful day more bearable, and it doesn't retrain the system that's producing the symptoms. A lot of people reach for it out of desperation to feel better, which is understandable, and it's worth making the choice with both sides in view.

Where Does It Sit in a POTS Plan?

Our team doesn't prescribe cannabis. The decision belongs with you and the physician who prescribes for you, in a place where it's legal. It's worth telling whoever tests you what you use and when, because THC changes heart rate and standing blood pressure (Jones, 2002).

If you use it and your standing symptoms are worse in the hour or 2 afterward, the studies in healthy people give a reason. If you're considering it for pain or sleep, the measured benefits are small and the dizziness risk rises with longer use. The treatments with evidence in POTS itself are covered in POTS treatment.

Medical Marijuana and POTS: FAQ