Following is information not verified or researched by me. The apparent author source is listed below. This information suggests certain circumstances in which using herbs may cause concerns. Since this information was not confirmed please use it in an advisory manner. To me this information suggests caution if considering using herbs.

• Echinacea,if used for more than eight consecutive weeks, could cause liver toxicity and should not be used with drugs such as anabolic steroids, amiodarone and methotrexate which are toxic to the liver as the affect may be additive.
  
  
• Feverfew, garlic, ginger, ginseng, and ginkgo biloba all affect bleeding time and should not be taken by patients using warfarin or by patients that have decreased platelet counts.
  
  
• St John's wort should not be taken with monoamine oxidase inhibitors or selective serotonin reuptake inhibitors like Prozac and Paxil until more information is available.
  
  
• Licorice, plantain, hawthorn and ginseng may interfere with digoxin therapy and valerian root should not be taken when barbiturates are used because it could cause an increase in the barbituate effects.
  
  
• 'Evening primrose oil and borage are contraindicated in patients taking anticonvulsants (eg clonazepam).
  
  
• lmmunostimulants such as echinacea and zinc should not be given with immuno suppressants such as corticosteroids (like prednisone) and cyclosporine and are contraindicated in patients suffering from rheumatoid arthritis, systemic lupus erythematosus and autoimmune hepatiitis.
  
  
• Source: Hans Larsen is a health sciences researcher living in Victoria, British Columbia from Alive Magazine March 1999 with some changes by D. Morrow