Herbal Supplements and Heart Medicines

How Herbal Remedies Affect Prescription Heart Drugs

Many people use herbal supplements and think they are always safe because they come from plants. This is not always true, especially for those already taking prescription medicine for their heart or blood vessels.

People often use supplements like ginkgo biloba, garlic, ginseng, hawthorn, soy, bergamot, and milk thistle for heart health, lowering cholesterol, or blood pressure. However, these supplements can interact with prescription medicines.

For example, doctors prescribe warfarin as a blood thinner to prevent stroke and heart attacks. If you take herbs such as ginkgo and garlic with warfarin, clopidogrel, or aspirin, your risk of bleeding goes up. Ginseng may weaken the effects of warfarin, making it less effective.

When people do not tell their doctor or pharmacist about their supplement use, it becomes harder to avoid dangerous mix-ups. Sharing information with your healthcare provider helps keep you safe. Here is a brief table showing some common herbs and how they may affect common heart prescriptions:

Herbal Supplement	Potential Issue with Heart Medication
Garlic	Raises the risk of bleeding with blood thinners.
Ginkgo biloba	Raises the risk of bleeding with blood thinners.
Ginseng	Reduces the effectiveness of warfarin.
Hawthorn	May alter the effects of beta-blockers and nitrates.
Licorice	Can intensify digoxin’s effects and lower warfarin’s
Saw Palmetto	Raises bleeding risk with blood thinners.
Danshen	Interacts with blood thinners and digoxin.
St. John’s Wort	Can reduce the effectiveness of statins and warfarin.
Evening primrose	Raises bleeding risk with blood thinners.
Coenzyme Q-10	Lowers warfarin effect and reduces blood pressure.

People with heart failure, arrhythmia, high blood pressure, high cholesterol, or coronary artery disease need to be especially careful. Medicines for these conditions often have a narrow safe range, and herbal products can tip the balance.

Common Interactions Between Herbs and Heart Medicines

Certain herbs and plant products can change how heart medications work. These changes can make prescription medicines less effective or cause more side effects.

Blood Thinners: Herbs like garlic, ginkgo, saw palmetto, evening primrose, and danshen raise the risk of serious bleeding. Even foods like soy and drinks like green tea can sometimes affect blood thinners.
Statins (Cholesterol-lowering Drugs): Herbs such as St. John’s wort and possibly milk thistle may make statins less effective.
Calcium Channel Blockers and Beta Blockers: Herbs like hawthorn and St. John’s wort can interfere with medicines like diltiazem, verapamil, or atenolol, which treat high blood pressure and abnormal heart rhythms.
Nitrates (for chest pain or heart failure): Hawthorn and other herbal remedies could change their effect, possibly leading to low blood pressure or other symptoms.
Blood Pressure Medication: Herbs including coenzyme Q-10, danshen, ginseng, and some herbal teas can lower blood pressure more than expected, causing dizziness or fainting.
Anti-rejection Medicine: Herbal supplements, especially St. John’s Wort, can make these drugs less effective, which is risky for people with heart transplants.

Other Possible Herbal Interactions

Some natural products such as flavonoids, ginger, bergamot, or extracts claiming heart benefits may cause unpredictable effects. Interactions can differ from person to person. Below is a quick list of some key heart conditions and which herbal products might affect them:

Arrhythmia: Hawthorn, danshen, licorice, ginger
Heart Failure & Myocardial Infarction: Digoxin interaction with herbal products; changes in blood pressure caused by coenzyme Q-10 or ginseng
High Cholesterol (Hypercholesterolemia): Statins affected by St. John’s wort or milk thistle
Hypertension (High Blood Pressure): Effects from ginseng, coenzyme Q-10, hawthorn, green tea, bergamot

Side Effects to Watch For

Easy bruising or bleeding.
Experiencing a rapid heartbeat or an irregular rhythm can be concerning.
Dizziness or sudden drops in blood pressure.
Muscle aches or weakness (when using statins and certain herbs).
Unusual swelling or allergic reactions.

Key Points

Not all herbs interact the same way with every drug.
Herbal supplement dosages are often not exact.
Some herbal products may have other ingredients or contaminants.

Tips for Using Herbal Supplements Safely

If you take prescriptions for heart disease or related problems, be careful about adding herbal remedies. Use these steps to lower the risk of side effects and drug interactions:

Tell Your Doctor and Pharmacist: Always let your healthcare providers know about every supplement or herbal product you use. This helps identify possible risks.
Ask Before Using: If you want to start a new supplement, check with your doctor or pharmacist first—especially if you have a heart condition or take blood thinners, statins, or beta-blockers.
Check for Warning Signs: Watch for new symptoms, such as:
- Sudden changes in blood pressure.
- Unexpected tiredness or shortness of breath.
- Rapid or irregular heartbeat.
- Increased bruising or bleeding.
Start with Small Amounts: If your healthcare provider says a supplement is safe, begin with the lowest possible dose.
Use Products from Trusted Sources: Buy herbal products from companies known for testing for purity. This reduces the risk of contaminants.
Understand Herbal Labels: Look for detailed ingredient lists and dosing information. Be wary of claims that seem too good to be true.

Safe Practices for Herbal Supplement Use

What to Do	Why It Matters
Communicate with the health team.	To avoid harmful interactions.
Follow dosing instructions.	Prevents accidental overdose or strong effects.
Observe changes in symptoms.	Early detection of side effects or drug problems.
Avoid mixing several supplements.	Lowers the chance of unknown herb-drug reactions.
Ignore unproven health claims.	Helps focus on what works and is safe.

Never stop or start any medicine or supplement suddenly without checking with your medical provider. Even “natural” products can be risky for heart health, especially in people with stroke, heart failure, coronary artery disease, or high cholesterol.