Skip to Content

St. john's wort Side Effects

Applies to st. john's wort: oral capsule, oral tablet

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Although not all side effects are known, St. John's wort is thought to be likely safe when taken by an adult for up to 12 weeks, or by a child age 6-17 for up to 8 weeks. St. John's wort may be unsafe when taken in large doses.

Stop using St. John's wort and call your healthcare provider at once if you have:

  • severe skin rash or irritation;

  • severe sunburn (redness, burning, blistering) after being outdoors; or

  • (if you are also taking an antidepressant or narcotic pain medicine) -- agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting.

Common side effects may include:

  • sleep problems (insomnia), strange dreams;

  • feeling anxious, irritable, or restless;

  • dry mouth, upset stomach, diarrhea;

  • skin rash, tingly feeling;

  • headache, dizziness; or

  • tired feeling.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Hide