Side Effects and Cautions
St. John's wort may cause increased sensitivity to sunlight. Other side effects can
- dry mouth
- gastrointestinal symptoms
- sexual dysfunction
Research shows that St. John's wort interacts with some drugs. The herb affects the way
the body processes or breaks down many drugs; in some cases, it may speed or slow a drug's
breakdown. Drugs that can be affected include:
- Birth control pills
- Cyclosporine, which prevents the body from rejecting transplanted organs
- Digoxin, which strengthens heart muscle contractions
- Indinavir and possibly other drugs used to control HIV infection
- Irinotecan and possibly other drugs used to treat cancer
- Warfarin and related anticoagulants
When combined with certain antidepressants, St. John's wort may increase side effects such
as nausea, anxiety, headache, and confusion.
St. John's wort is not a proven therapy for depression. If depression is not adequately
treated, it can become severe. Anyone who may have depression should see a health care
provider. There are effective proven therapies available.
Tell your health care providers about any complementary and alternative practices you use.
Give them a full picture of what you do to manage your health. This will help ensure
coordinated and safe care.