Herbal supplements and heart medicines may not mix

Many herbal supplements can interact with prescription drugs. Some of these interactions can be life-threatening.

By Mayo Clinic Staff

Herbal supplements are natural, so they must be safe, right? Not necessarily.

Herbal supplements can have strong effects in the body. Some can interact with prescription medications used to treat heart and circulatory problems, such as high blood pressure and heart failure. Some of these interactions can even be dangerous.

About half of U.S. adults report taking supplements. But research suggests that most don't tell their doctors about this use — even those who also take prescription medications.

Yet many herbal supplements may interact with prescription medications, including some used to prevent or treat heart disease.

That's why it's so important to talk with your doctor before taking herbal supplements if you take prescription medications. Your doctor and your pharmacist can help you avoid risky interactions.

Herbal supplements and drug interactions

Several popular herbal supplements interact with common heart medications. This list covers only some interactions. It's important to talk to your doctor before taking any herbal supplements if you take prescription medications.

Coenzyme Q10

Taking coenzyme Q10 can decrease:

  • The effectiveness of warfarin (Jantoven)
  • Your blood pressure if you also take a calcium channel blocker, such as diltiazem (Cardizem, Tiazac, others)


Danshen can interact strongly with certain heart medications, including:

  • Anticoagulants. Taking danshen significantly increases your risk of bleeding if you also take warfarin or another anticoagulant, such as clopidogrel (Plavix) or aspirin.
  • Calcium channel blockers. Taking danshen increases your risk of low blood pressure if you also take diltiazem or another calcium channel blocker.
  • Digoxin (Lanoxin). Taking danshen increases the effects of digoxin — which is used to treat a variety of heart conditions — and puts you at risk of irregular heartbeat (arrhythmia).

Evening primrose

Evening primrose may increase your risk of bleeding if you also take an anticoagulant, such as:

  • Aspirin
  • Clopidogrel
  • Warfarin


Garlic increases your risk of bleeding if you also take an anticoagulant, such as:

  • Aspirin
  • Clopidogrel
  • Warfarin

Gingko biloba

Ginkgo biloba increases your risk of bleeding if you also take:

  • Aspirin
  • Clopidogrel
  • Warfarin


Taking ginseng with warfarin decreases warfarin's effectiveness.


Hawthorn might interact with:

  • Beta blockers, such as atenolol (Tenormin), nadolol (Corgard) or propranolol (Inderal, Innopran, Hemangeol)
  • Calcium channel blockers, such as diltiazem, nifedipine (Procardia) and verapamil (Calan SR, Verelan)
  • Nitrates, such as nitroglycerin (Nitrostat, Nitro-Dur, others) and isosorbide (Dilatrate-SR, Isordil)
  • Digoxin


Licorice decreases levels of warfarin and can increase the effects of digoxin.

Saw palmetto

Saw palmetto increases your risk of bleeding if you also take:

  • Aspirin
  • Clopidogrel
  • Warfarin

St. John's wort

Taking St. John's wort reduces the effectiveness of:

  • Calcium channel blockers
  • Digoxin
  • Warfarin
  • Statins, such as atorvastatin (Lipitor), lovastatin (Altoprev) and simvastatin (Flolipid, Zocor)

Playing it safe with herbal supplements

If your doctor tells you it's OK to use an herbal supplement combined with a medication, make sure you follow dosing instructions carefully. Watch for any signs that you could be having a drug interaction, such as:

  • Rapid heartbeat
  • Changes in blood pressure
Nov. 14, 2020 See more In-depth

See also

  1. A Very Happy Brain
  2. Acupuncture for back pain?
  3. Alternative cancer treatments: 10 options to consider
  4. Aromatherapy: Is it worthwhile?
  5. Candida cleanse diet
  6. CBD safety
  7. Chronic fatigue: Can a natural remedy boost my energy?
  8. Colloidal silver supplements
  9. Colon cleansing
  10. Considering complementary therapy
  11. Cupping therapy: Can it relieve fibromyalgia pain?
  12. Detox foot pads
  13. Diabetes treatment: Can cinnamon lower blood sugar?
  14. Do infrared saunas have any health benefits?
  15. Prickly pear cactus
  16. Ear candling
  17. Ear infection treatment: Do alternative therapies work?
  18. Echinacea: Is it effective for the common cold?
  19. Ginkgo biloba: Can it prevent memory loss?
  20. Herbal supplements: Not risk-free
  21. Herbal supplements: Safety first
  22. Huperzine A: Can it treat Alzheimer's?
  23. Integrative medicine: Different techniques, one goal
  24. Integrative medicine: Find out what works
  25. Kombucha tea
  26. Kratom: Unsafe and ineffective
  27. Kratom and pregnancy: Not a safe mix
  28. Kratom for opioid withdrawal
  29. Learn to reduce stress through mindful living
  30. Massage
  31. Medical marijuana
  32. Meditation 2.0: A new way to meditate
  33. Mindfulness exercises
  34. Mindfulness practice: Can it reduce symptoms of MS?
  35. Miracle cure or marketing scam?
  36. Natural aphrodisiacs
  37. Natural remedies for depression: Are they effective?
  38. Oil of oregano: Can it treat sinusitis?
  39. Pet therapy
  40. Probiotics and prebiotics
  41. Fish oil supplements
  42. Tai chi
  43. Tai Chi and Cardiac Rehab
  44. Valerian: A safe and effective herbal sleep aid?
  45. Tai chi
  46. Vitamin B-12 and Alzheimer's
  47. Alternative psoriasis treatments
  48. What is hot yoga?
  49. What is reflexology?
  50. Wheatgrass
  51. Why aromatherapy is showing up in hospital surgical units
  52. Yucca: Can it relieve arthritis pain?
  53. Do zinc supplements shorten colds?