Most of us think of herbal supplements as the gentle option, something safer than a prescription. Many people take them alongside everyday medications without a second thought.
But that assumption can be risky, especially for the millions of Americans who take blood pressure medication every day.
The NIH's National Center for Complementary and Integrative Health (NCCIH) warns that some popular supplements can either blunt antihypertensive drugs or raise blood pressure on their own. Here are seven worth flagging with your doctor or pharmacist.
St. John's wort may weaken calcium channel blockers
St. John's wort is best known as an herbal mood booster. According to the NCCIH, it is also one of the most interaction-prone herbs on the market.
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The agency says it can weaken the effects of many critically important medicines, including heart drugs such as digoxin and ivabradine. Clinical studies have also shown it lowers blood levels of calcium channel blockers like nifedipine and verapamil.
That can quietly reduce how much your pill is actually doing to control your pressure.
Licorice root may raise blood pressure directly
Black licorice candy and licorice root supplements contain glycyrrhizin, a compound that makes the body hold on to sodium and lose potassium.
The NCCIH warns that even small amounts of glycyrrhizin have been linked to severe adverse effects in people with high blood pressure, heart conditions or kidney disease. That effect can directly undermine ACE inhibitors and diuretics.
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High-dose green tea extract can blunt the beta blocker nadolol
Green tea sounds like the healthiest drink around. Concentrated green tea extracts, however, behave more like a drug.
The NCCIH states that green tea at high doses "has been shown to reduce blood levels and, therefore, the effectiveness of the drug nadolol." Nadolol is a beta-blocker used for high blood pressure and heart problems.
Bitter orange can push blood pressure up like a stimulant
Bitter orange is often added to weight loss and energy supplements. It contains synephrine, a stimulant similar to the chemicals in ephedra.
The NCCIH lists bitter orange, ephedra, ginseng and licorice root among herbs that may raise blood pressure. For someone on antihypertensive medication, that can cancel out part of what the pill is doing.
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Yohimbe may trigger spikes in blood pressure
Yohimbe is sold mainly for sexual performance. The NCCIH says yohimbine, its active component, has been linked to irregular heartbeat, blood pressure problems, heart attacks and seizures.
The agency specifically warns people with high blood pressure not to take yohimbe supplements.
Potassium supplements combined with ACE inhibitors can push levels dangerously high
ACE inhibitors such as lisinopril and enalapril already raise potassium in the blood. They do this by blocking the hormone that normally helps the kidneys clear it.
Adding a potassium supplement, a potassium-based salt substitute or a potassium-sparing diuretic can tip the balance into hyperkalemia. That can cause dangerous heart rhythm problems.
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The FDA prescribing information for lisinopril specifically names these as risk factors.
Asian ginseng may interact with calcium channel blockers
The NCCIH flags uncertainty about Asian ginseng's interactions with calcium channel blockers and other blood pressure medications.
The agency also lists ginseng among herbs that may raise blood pressure. That means its effects can swing in either direction depending on the product and the dose.
Tell your doctor and pharmacist about everything you take
Bring a complete list of everything you take, including over-the-counter herbs and vitamins, to every medical visit. The NCCIH advises telling your health care provider about all dietary supplements, especially before you start or stop one.
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This article is made and published by Mie Hermansen, who may have used AI in the preparation.