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Table 1 Key safety issuesa

From: Buyer beware? Does the information provided with herbal products available over the counter enable safe use?

St John's wort Ginkgo Asian ginseng Garlic Echinacea
Sensitivity to sunlight Increased bleeding risk People with diabetes should use extra caution, especially if using medicines to lower blood sugar or taking other herbs ... also thought to lower blood sugar. Can thin the blood Allergy to related plants in daisy family
  Bleeding disorders   Use with caution if planning to have surgery or dental work. People with asthma or atopy may be more likely to have an allergic reaction.
  Scheduled surgery or dental procedures   Use with caution if you have a bleeding disorder.  
Antidepressants Anticoagulant drugs   Interferes with effectiveness of saquinavir, a drug used to treat HIV  
Oral contraceptives     
Indinavir and possibly other HIV medications     
Irinotecan and possibly other anticancer drugs     
Seizure control drugs     
Warfarin and related anticoagulants     
Side effects     
Anxiety Headache Headache Breath and body odour Allergic reactions including rashes
Dry mouth Nausea Sleep problems Heartburn Increased asthma
Dizziness Gastrointestinal upset Gastrointestinal problems Upset stomach Anaphylaxis
Gastrointestinal symptoms Diarrhoea Allergic reactions Allergic reactions Gastrointestinal side effects
Fatigue Dizziness Breast tenderness   
Headache Allergic skin reactions Menstrual irregularities   
Sexual dysfunction More severe allergic reactions occasionally reported High blood pressure   
  1. aAs identified in the NCCAM Herbs at a Glance monographs [13].