Heart Trouble? 15 Herbal Remedies to Avoid

Millions of Americans take herbal remedies for ailments ranging from high cholesterol to depression. Although they're widely viewed as safe, these products can actually cause serious interactions in people who are also taking prescription drugs for heart problems. In a 2010 report by Mayo Clinic researchers, more than 25 herbal products were listed as being dangerous for heart patients on medication. Here, herbal products that heart patients should avoid (using data from the report, as well as from the National Institutes for Health and the Natural Standard Research Collaboration) to stay safe while taking prescription drugs.

What it is: A member of the onion family, available commercially as an oil, extract, or pill (in addition to its natural state).

What it’s used for: To lower total and LDL (bad) cholesterol, as well as blood pressure. Also used as a blood thinner and to combat atherosclerosis.

The risk: Garlic’s blood-thinning properties may increase risk of bleeding associated with warfarin, a blood thinning drug commonly prescribed to people with heart-rhythm disorders and to people who have had heart attacks or heart-valve replacements, as well as aspirin.

What it is: The fruit of the palmetto tree (a type of palm tree), available as a capsule, liquid, or tea.

What it’s used for: Primarily used to fight the urinary problems caused by an enlarged prostate gland, saw palmetto is also used to combat hair loss, chronic pelvic pain, and decreased sex drive.

The risk: Like garlic, saw palmetto also increases the risk of bleeding associated with warfarin, as well as aspirin, antiplatelet drugs, or NSAIDs.

What it is: The extract of the leaves of the ginkgo plant (also known as the maidenhair tree), sold as a capsule or tea.

What it’s used for: Ginkgo is mainly used to improve memory and prevent dementia (including Alzheimer’s disease), but it has also been used to treat asthma, ringing in the ears, sexual dysfunction, and leg pain caused by poor circulation.

The risk: Gingko also increases the risk of bleeding associated with aspirin and warfarin.

What it is: The roots and herb of the echinacea plant, dried or extracted and sold as a capsule, tea, or juice.

What it’s used for: To prevent colds and flu and boost the immune system.

The risk: Echinacea can also increase risk of bleeding when taken along with warfarin, anti-platelet drugs, and NSAIDs.

What it is: A yellow-flowered plant, Hypericum perforatum, that is sold as a capsule, tea, or liquid extract.

What it’s used for: Primarily used to treat depression and anxiety, St. John’s wort is also used as a sedative in sleep disorders.

The risk: Affects how the body absorbs dozens of prescription medications and may diminish the efficacy of statins and beta-blockers (a class of drugs used to treat high blood pressure and heart-rhythm disorders). It may also increase risk of bleeding when taken with aspirin, warfarin, anti-platelet drugs, and NSAIDs.

What it is: The leaves of the Camellia sinensis plant. Usually steeped in water as a tea, but also available as a capsule or extract.

What it’s used for: To lose weight, improve mental alertness, lower cholesterol, and prevent cancer.

The risk: Green tea may interfere with adenosine, a medication for irregular heart rhythms. Because green tea contains vitamin K, it can counteract the effect of warfarin, as well as increase risk of bleeding if you take green tea and aspirin together. The caffeine in green tea also could interfere with beta-blockers.

What it is: A plant in the pea family, the dried leaves of which are ground up and sold as capsules.

What it's used for: To lower total and LDL (bad) cholesterol, and to reduce the plaques caused by atherosclerosis.

The risk: Because alfalfa contains vitamin K, it can also increase risk of bleeding when you take warfarin.

What it is: A root, often used in cooking, that is also processed and sold as a capsule.

What it’s used for: Ginger has been used for centuries to treat various stomach ailments (such as nausea, diarrhea, and stomachache). It is also used to treat joint and muscle pain.

The risk: Ginger might interfere with blood clotting, although more research is needed on this. To be safe, speak to your doctor if you're taking ginger supplements as well as warfarin or aspirin.

What it is: The dried extract of the bilberry fruit, which is very similar to the blueberry. Sold as a capsule.

What it’s used for: Bilberry is used to treat problems associated with poor circulation, most notably varicose veins and venous insufficiency, in addition to diarrhea, skin problems, eyestrain, and menstrual cramps.

The risk: Bilberry may improve blood circulation, but speak to your doctor before taking it along with blood thinners, because it may also increase the risk of bleeding associated with warfarin.

What it is: An herb, native to Asia, that has been used in traditional medicine for centuries and is now sold as a capsule.

What it’s used for: To boost energy, stamina, and the immune system. Also used to lower LDL cholesterol and blood pressure.

The risk: When overused, ginseng can diminish the effect of warfarin. It can also interact with other heart medications, such as calcium channel blockers.

What it is: The juice cartons in the supermarket, right next to the orange juice.

What it’s used for: To speed up weight loss and to promote heart health.

The risk: Grapefruit juice interferes with an enzyme that is essential for properly absorbing medications, including cholesterol-lowering statins such as Lipitor and Zocor, which intensifies the effect of those drugs.

What it is: The pulp of the aloe vera plant.

What it’s used for: In addition to its familiar use as a lotion and salve, aloe is taken orally to treat serious health conditions including arthritis, epilepsy, diabetes, and asthma.

The risk: Aloe vera can cause a drop in the blood’s potassium level, which in turn can lead to heart rhythm problems, as well as complications in heart patients taking the drug digoxin for arrhythmia or congestive heart failure.

What it is: The extract of the root of the black cohosh plant, Actaea racemosa. Sold as a capsule.

What it’s used for: Black cohosh is mainly used to assuage the symptoms of menopause (hot flashes, vaginal dryness, night sweats), but it has also been used to treat joint and muscle pain.

The risk: Black cohosh may interfere with certain prescription medications, including beta-blockers and calcium-channel blockers. It also carries a risk of liver damage. Black cohosh could also increase risk of bleeding when taken with warfarin, aspirin, antiplatelet drugs, and NSAIDs.

What it is: A flowering shrub related to the rosebush.

What it’s used for: The fruit of the hawthorn shrub has been used to treat the symptoms of heart disease for hundreds of years, while the leaf and flower are also used to treat heart failure.

The risk: Hawthorn may interact negatively with prescription heart-failure medications. Speak to your doctor before incorporating it into your diet.

What it is: The dried extract of the root of the licorice plant, sold as a capsule.

What it’s used for: Licorice root is used to treat ulcers and other stomach ailments, bronchitis and sore throat, and some viral infections.

The risk: Licorice root could interfere with ace-inhibitors or diuretics that regulate blood pressure.