What 7 Days of Cannabidiol Does to Your Circulation
When stress tries to jack up your blood pressure, could CBD help your vessels whisper “not today”? New human data gives us clues.
You know those moments, you’re stuck in traffic, your phone rings nonstop, that deadline looms, and you feel that internal squeeze. Blood pressure climbs, your arteries tighten, and your heart works harder. Over days, weeks, years, those little surges take a toll.
If there’s a way to make your vascular system more resilient to soften those jolts, people want to know. That’s where cannabidiol (CBD) comes in, with increasing interest in what it does beyond just calming the mind.
One recent trial asked: What happens when healthy men take CBD for a week? Does it keep helping blood pressure and vascular function, or does the body adapt? Let’s dive in.
A Week of CBD in Healthy Men
Researchers in the UK recruited twenty-six healthy young men to take part in a controlled trial. Half of them received a daily oral dose of 600 mg of CBD for seven days, while the others took a placebo. The design was randomized, double-blind, and placebo-controlled—the strongest way to minimize bias and get reliable results.
The research team wanted more than a blood pressure reading. They tracked:
- Blood pressure and heart rate at rest.
- The body’s reaction during stress tests (like exercise and mental tasks).
- Arterial stiffness and flow, using ultrasound and specialized cardiovascular equipment.
- Endothelial function, which reflects how well vessels widen in response to changes in blood flow.
This wasn’t just about whether CBD “works.” It was about painting a detailed picture of how it interacts with the cardiovascular system.
What Happened to Blood Pressure?
On the first day, CBD lowered resting blood pressure slightly—just a couple of points on average. Small, yes, but even modest reductions matter. Epidemiological research shows that lowering systolic blood pressure by as little as 2 mmHg can reduce the risk of heart attack and stroke over a lifetime.
By day seven, however, that effect on resting blood pressure had largely disappeared. The body seemed to adapt, suggesting CBD’s initial lowering effect doesn’t keep accumulating at that high daily dose.
But the more striking results appeared under pressure. When participants faced physical or mental stress tests, those taking CBD experienced smaller spikes in blood pressure compared to the placebo group. Stress normally sends the cardiovascular system into overdrive, but CBD appeared to soften that reaction, shaving off several millimeters of mercury from the peak rise.
That may not sound dramatic, but in the context of heart health, consistently lower spikes could reduce the wear and tear stress places on vessels over time.
A Closer Look at the Blood Vessels
The researchers didn’t stop at blood pressure. They also zoomed in on the vessels themselves. After a week of CBD, participants showed:
- Wider carotid arteries: These arteries, which carry blood to the brain, expanded slightly in diameter, suggesting smoother flow.
- Reduced stiffness: Arteries were more flexible, an encouraging sign since stiff vessels are linked to higher cardiovascular risk.
- Better endothelial function: The inner lining of vessels responded more effectively to changes in blood flow, a marker of vascular health.
These findings matter because cardiovascular wellness isn’t just about the pressure inside the vessels; it’s also about how healthy, flexible, and responsive those vessels are. Stiff, unresponsive arteries are a major predictor of future heart problems.
Safety and Tolerability
Taking 600 mg of CBD daily is considered a high dose, and yet participants tolerated it well. A few reported mild effects such as headaches, changes in appetite, or trouble sleeping. Importantly, no serious adverse events were recorded.
For anyone curious about CBD’s long-term cardiovascular potential, this is encouraging. It suggests that, at least in healthy young men, CBD doesn’t introduce major safety concerns when taken at high doses for a week.
What This Means for Your Circulation
So what can you take away from this study?
- CBD may act as a stress buffer. Even if baseline blood pressure doesn’t stay lower, the compound seems to reduce the impact of stressful moments, when your heart and vessels usually take the hardest hit.
- Your vessels might thank you. Improvements in artery flexibility and endothelial function hint that CBD could support vascular health in ways beyond just lowering numbers.
- Tolerance is real. The fading effect on resting blood pressure suggests the body adapts. That means CBD isn’t a quick-fix replacement for medications or lifestyle changes.
- Side effects are mild but worth noting. No serious issues were reported, but a few participants experienced headaches, appetite changes, or trouble sleeping.
- Lifestyle still matters most. Exercise, diet, sleep, and stress management remain the cornerstones of cardiovascular health. CBD might complement those habits, especially for people who tend to see their blood pressure surge during tense moments.
It also adds weight to the idea that CBD may shine not in lowering day-to-day blood pressure, but in helping the body handle stress without such dramatic spikes. For people whose blood pressure tends to surge in tense moments, that could be a meaningful benefit.
Original Study Section
Title: The effects of acute and sustained cannabidiol dosing for seven days on the haemodynamics in healthy men: A randomised controlled trial
Date: March 2020
Authors: Salahaden R. Sultan, Saoirse E. O’Sullivan, Timothy J. England
Link: Read it on PubMed