Written by Nicole Andonian, MD | Reviewed by Karen Hovav, MD, FAAP

Published on August 1, 2024

Key takeaways:

• High blood pressure can be treated with a combination of lifestyle modifications, supplements, and prescription medications. 
• Supplements that can help reduce blood pressure include omega-3 fatty acids, magnesium, and hibiscus tea.
• Talk with your healthcare professional before starting a new supplement as some interact with other medications. 

Table of contents

Safety

Best supplements

When to get care

Bottom line

References

andreswd/E+ via Getty Images

High blood pressure is a common condition affecting nearly half of adults in the U.S. This happens when the force of blood pushing against your blood vessels is too high. Having high blood pressure — also called hypertension — increases your risk for strokes and heart attacks. 

Hypertension is diagnosed when the top number of your blood pressure is above 130, and/or the bottom number is greater than 80. High blood pressure can be treated with lifestyle modifications, like diet and exercise. Prescription medications are often needed as well. 

But, can you also use supplements to lower your blood pressure? Here we’ll discuss what the research says about which supplements are the best for high blood pressure.  

Are supplements a safe way to manage blood pressure?

If you have mild hypertension, supplements may be a safe way to manage blood pressure, along with lifestyle modifications like diet and exercise. If your healthcare professional recommends a prescription medication for high blood pressure, you might consider taking a supplement along with that medication. 

It’s important to have a conversation with your healthcare professional before starting a new supplement. They can share their thoughts on managing your blood pressure with supplements, and let you know of any possible interactions with other medications you take. This will be important to know before adding a new medication, even if it’s a “natural” supplement.

Keep in mind that supplements aren’t regulated the same way as prescription medications. They don’t need to go through testing for FDA approval. And the FDA doesn’t routinely verify that supplements contain what they advertise. To help you choose safe supplements, you can look for third-party verifications, which mean they’ve been tested for ingredients and contaminants. 

Best supplements for lowering blood pressure

There are many supplements that health experts claim may help lower your blood pressure. Since supplements aren’t well regulated, it’s hard to know what’s just a myth versus what’s actually useful. We did a deep dive into the evidence for popular supplements that claim to help lower blood pressure. 

1. Omega-3 fatty acids

What it is: Omega-3s are fatty acids found in fish, like salmon and trout, and some plant sources, like walnuts and flaxseeds. They can affect how much your blood vessels squeeze, called vasoconstriction. Vasoconstriction helps to determine your blood pressure. 

What the research says: Omega-3 fatty acids have been shown to lower blood pressure by a few points. They can also decrease the amount of plaque in arteries, decrease inflammation, and lower triglyceride levels. So omega-3 fatty acids work in multiple ways to reduce your chance of a heart attack.

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Potential risks: There are occasional mild side effects to omega-3s. These include bad breath, heartburn, bad-smelling sweat, and gastrointestinal issues like nausea and diarrhea. 

How quickly it works: We aren’t entirely sure how quickly omega-3s start to work. Most of the studies looking at the effect of omega-3s on blood pressure and the cardiovascular system see an effect around 8 weeks. 

Worth a try? Yes. Omega-3 fatty acids have little downside. And they can improve several cardiovascular risk factors, including blood pressure. 

2. Potassium

What it is: Potassium is an essential mineral that affects several organ systems in your body. It’s very important in helping your heart and blood vessels pump blood normally. Potassium works on the muscles in your blood vessels, allowing them to relax.

What the research says: Low levels of potassium can cause the blood vessels to be tighter, or constrict, leading to higher blood pressure. Potassium levels can be checked by a blood test. If potassium levels are low, increasing potassium in your diet or with a supplement can help decrease blood pressure. 

Potential risks: Most people experience only mild side effects like nausea or diarrhea. Really high levels of potassium can cause a lot of serious issues, like abnormal heart rhythms that can even be deadly. People with kidney disease or who are on certain cardiac medications are typically the ones at risk for really high levels of potassium. 

How quickly it works: Oral potassium supplementation usually takes a few weeks to affect your blood pressure. This will also depend on what your current level of potassium and other electrolytes, like sodium, are. 

Worth a try? For the right person, yes. Work with your healthcare professional to check your current potassium level and kidney function before starting a potassium supplement. 

3. Magnesium

What it is: Magnesium is another mineral that’s essential in your body and is important in the regulation of blood pressure. Magnesium helps counteract the effects of calcium on your blood vessels. This is important because calcium causes your blood vessels to constrict, leading to higher blood pressure. Magnesium also helps protect the walls of the vessels from injury caused by harmful substances. 

What the research says: Adding magnesium supplements improves both systolic and diastolic blood pressure by a few points. The effect is greatest in people with high blood pressure (whether or not they’re taking medication). If a person has normal blood pressure on medication, adding magnesium doesn’t seem to give additional benefit. 

Potential risks: Side effects of taking magnesium are usually mild and temporary. They can include nausea, gastrointestinal (GI) upset, and low blood pressure.

How quickly it works: You’ll see an effect on your blood pressure after about 1 month of taking magnesium. 

Worth a try? Yes. Magnesium can help your blood pressure and has minimal side effects. And in addition to potentially lowering your blood pressure, it has other benefits like helping with sleep and mood. 

4. CoQ10

What it is: Coenzyme Q10 (CoQ10) is an antioxidant that naturally exists all over the body, including the heart, liver, and kidneys. There’s a link between low CoQ10, blood pressure, and heart disease. In fact, 3 out of 4 people with heart disease have low levels of CoQ10.

What the research says: Although results are mixed, CoQ10 has been shown to improve blood pressure in people who have diagnosed hypertension. It doesn’t lower blood pressure in people who have normal blood pressure. But, its effects on reducing the risk of heart disease have been inconclusive so far. 

Potential risks: CoQ10 can cause mild side effects like nausea and difficulty sleeping. It can interact with the blood thinner warfarin (Coumadin) as well as insulin. 

How quickly it works: Supplementation with CoQ10 for at least 3 weeks is needed to lower blood pressure. 

Worth a try? Maybe. More data is needed to really know if CoQ10 is helpful in lowering blood pressure. 

5. Vitamin D 

What it is: Vitamin D is an essential vitamin that helps with calcium absorption and bone formation. It also plays a role in inflammation and heart disease. Vitamin D can be increased by food sources and sun exposure. 

What the research says: The data is a bit confusing here. People with low vitamin D levels are more likely to have high blood pressure. But most studies don’t show a change in blood pressure when people take vitamin D supplements. The results aren’t straightforward. Some studies found that when vitamin D was added to a blood pressure medication, it did help to lower the blood pressure. But the results aren’t consistent. 

Potential risks: Vitamin D supplementation doesn’t really have any side effects. But taking too much vitamin D for a while can be toxic. Vitamin D toxicity can result in anything from kidney failure to a heart arrhythmia that leads to death. 

How quickly it works: It’s hard to say, since most studies didn’t find vitamin D effective for blood pressure.  

Worth a try? No. There isn’t enough evidence that vitamin D supplementation is helpful for blood pressure. But many people are low in vitamin D, so you might want to supplement for other reasons. Vitamin D is important in preventing osteoporosis, especially in women. Be mindful to follow the instructions for vitamin D dosage so you don’t take too much. 

6. Vitamin C

What it is: Vitamin C is another essential vitamin. Interestingly, humans cannot make vitamin C. We have to consume all the vitamin C we need in our diet. It’s important for everything from metabolism to being an antioxidant. 

What the research says: Some data point to vitamin C being protective for cardiovascular disease. But this is another vitamin with tricky evidence. Many studies have found that supplementing with vitamin C has minimal or no effect on blood pressure. But other studies did find that blood pressure was lower after taking oral vitamin C. More research studies are needed to figure out the right answer. 

Potential risks: Vitamin C is pretty safe, and has a low chance of side effects like nausea and other GI issues. 

How quickly it works: We don’t really know. The studies that found a positive effect on blood pressure looked at effects over, on average, 8 weeks. 

Worth a try? Probably not. There isn’t enough evidence yet that it helps lower blood pressure. Vitamin C is an important nutrient in your overall health, but most people will get enough vitamin C through their diet.  

7. Beetroot 

What it is: Beets, or sometimes called beetroots, are a root vegetable. They can be eaten whole (usually added to salads), enjoyed as beet juice, or taken as a supplement. They are typically dark red in color and are full of nutrients — including fiber, antioxidants, and nitrates. Nitrates are thought to play a key role in reducing blood pressure. 

What the research says: A large study that compared many smaller studies looking at the consumption of beet juice saw an improvement in systolic blood pressure (the top number of your blood pressure). Beetroot juice didn’t change the diastolic blood pressure (the bottom number). Some studies in animals also show that beet juice (or nitrate supplements) can counteract the effects of salt in raising blood pressure. 

Potential risks: Consuming beets in regular amounts doesn’t have any known side effects. Consuming large amounts of beets may cause GI upset due to the large fiber content. 

How quickly it works: Some studies saw improvement in blood pressure in as little as 3 days. But the effects were stronger if people were treated for more than 8 weeks.  

Worth a try? Yes, if you have the type of blood pressure in which the top number is high, beetroot is a helpful supplement. If your diastolic blood pressure is high, beetroot probably won’t help. Beets are a delicious food and full of many nutrients. Consider consuming beets, or beet juice, as part of a balanced and nutritious diet. 

8. Hibiscus 

What it is: Hibiscus (Hibiscus sabdariffa) is an herb that’s used to make tea. It’s actually one of the most common ingredients in tea sold in the U.S. 

What the research says: Several studies have shown the benefit of drinking hibiscus tea in lowering blood pressure. It seems to affect the systolic blood pressure (top number) more than diastolic. Hibiscus is beneficial if you have mild high blood pressure (stage 1 hypertension). 

Potential risks: The side effects of drinking hibiscus tea are very uncommon. Most people tolerate hibiscus well. 

How quickly it works: The blood-pressure-lowering effects of hibiscus tea seem to show at about 1 month of drinking the tea regularly.

Worth a try? Yes, incorporating hibiscus tea into a diet and lifestyle modification regimen to reduce blood pressure is not only easy, but it can also be effective. 

9. Garlic

What it is: Garlic is exactly what you think. It has been used for years to help with the common cold, as well as some cardiac diseases. The garlic bulb can be made into a powder and taken as a pill. 

What the research says: Garlic has been shown in several studies to reduce blood pressure in people both with and without high blood pressure. It has also been shown to improve high cholesterol. But, there’s some debate about the design of certain research studies as well as the inconsistency of garlic supplements available on the market. 

Potential risks: Garlic is safe for most people to eat or consume in supplements. Some side effects include bad breath or body odor. Garlic supplements can sometimes interfere with other medications, like blood thinners and HIV medications. 

How quickly it works: Studies haven’t specifically looked at how long it takes for garlic to take effect. Most studies do show an effect around the 8-week mark. 

Worth a try? Although there’s some debate over the usefulness of garlic in lowering blood pressure, recent studies have shown that garlic supplements can lower blood pressure. The key may be in finding a good quality garlic supplement. It’s worth a try, but talk with a healthcare professional to make sure it doesn’t interact with any of your other medications. 

10. Green tea

What it is: Green tea is a flavorful tea consumed all over the world. It has been used for health purposes for thousands of years in Japan and China. Green tea extract can be taken as a supplement, too. It’s full of antioxidants and has compounds like polyphenols and catechins that may help in regulating blood pressure. Green tea has many health benefits including lowering cholesterol and improving blood sugar.  

What the research says: Studies show that drinking green tea can lower both systolic and diastolic blood pressure. The effect was most notable in people with stage 1 hypertension. But there’s a benefit even if you have prehypertension. 

Potential health risks: Drinking green tea is safe for most people. Green tea does have caffeine so you may need to monitor your intake, especially if pregnant or breastfeeding. Rarely, green tea can affect liver function and also interact with some medications. 

How quickly it works: Studies show a positive effect of green tea after 12 weeks of regular drinking. 

Worth a try? Yes. Green tea is an easy and flavorful addition to your diet that provides several health benefits, including lowering blood pressure. 

When to talk with your healthcare professional about your blood pressure

If you have several high blood pressure readings after measuring your blood pressure at different times of day over several days, it’s time to talk with your healthcare professional. 

For mild hypertension, experts recommend starting prescription blood pressure medications after about 6 months of trying to lower your blood pressure with lifestyle modifications. If your blood pressure is higher than 140/90, prescription medications are recommended. 

You can work with your healthcare professional to come up with a plan that works well for you. This may involve lifestyle modifications, supplements, and prescription medications. 

The bottom line

High blood pressure is a risk factor for other things like stroke, heart attacks, and even death. A first step in managing blood pressure may be diet and lifestyle modifications. If you’re interested in using supplements to help lower your blood pressure, you have a lot to choose from. Supplements like magnesium, omega-3 fatty acids, and green tea extract are just some of the options that can help. But supplements may not be enough to lower your blood pressure. Each person’s body is different. Together with your healthcare professional, you can come up with a plan to manage your high blood pressure and lower your risk of other serious diseases. 

Why trust our experts?

Written by:

Nicole Andonian, MD

Nicole Andonian, MD, is a private practice anesthesiologist in Orange County, California. Her focus is in general anesthesia, regional anesthesia, and acute pain management.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

Reviewed by:

Karen Hovav, MD, FAAP

Karen Hovav, MD, FAAP, has more than 15 years of experience as an attending pediatrician in a variety of clinical settings. She has worked in a large academic center in an urban city, a small community hospital, a private practice, and an urgent care clinic.

Our editorial standards

Meet our experts

References

American Heart Association. (2019). Beetroot, nitrate supplements could help prevent salt-induced hypertension.

American Heart Association. (2021). If slightly high blood pressure doesn’t respond to lifestyle change, medication can help: American Heart Association scientific statement.

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