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St. John's Wort

Medically reviewed by Last updated on Nov 30, 2021.

What are other common names?

  • Hypericum perforatum
  • Hypericum
  • Amber
  • Amber Touch-and-Heal
  • Barbe de Saint-Jean
  • Chase-Devil
  • Chasse-diable
  • Demon Chaser
  • Esbericum
  • Fuga Daemonum
  • Goatweed
  • Hardhay
  • Herbe Aux Fées
  • Herbe Aux Mille Vertus
  • Herbe Aux Piqûres
  • Herbe de la Saint-Jean
  • Herbe de Saint Éloi
  • Herbe du Charpentier
  • Herbe Percée
  • Herbe à la Brûlure
  • Herbe à Mille Trous
  • Hierba de San Juan
  • Hypereikon
  • Hyperforat
  • Hyperici Herba
  • Hyperiforce
  • John's Wort
  • Kira
  • Klamath Weed
  • LI 160
  • Millepertuis
  • Neuroplant
  • Psychotonin
  • Rosin Rose
  • Saynt Johannes Wort
  • Sedariston
  • SJW
  • St John Wort
  • St John's Wort
  • St. John Wort
  • STEI 300
  • Tipton Weed
  • Tipton's Weed
  • WS 5573
  • Ze 117

What is this product used for?

St. John's wort may help with low mood. It may also help with some symptoms of premenstrual syndrome and menopause. It may help treat certain virus infections and help to heal wounds.

What are the precautions when taking this product?

  • Always check with your doctor before you use a natural product. Some products may not mix well with other drugs or natural products.

  • This product interferes with MANY drugs. It reduces the effectiveness of many drugs. It increases side effects of some drugs. Talk with your doctor before you start using this product.

  • Do not use this product if you are taking other products that increase serotonin in your body, such as some cough medicines, SSRIs, or MAO inhibitors. These are products like dextromethorphan, fluoxetine, citalopram, isocarboxazid, phenelzine, and tranylcypromine.

  • Be sure to tell your doctor that you take this product if you are scheduled for surgery or tests.

  • You may get sunburned more easily while using this product. Avoid sun, sunlamps, and tanning beds. Use sunscreen and wear clothing and eyewear that protects you from the sun.

  • Do not use this product if you are pregnant or plan to become pregnant soon. Use birth control you can trust while taking this product.

  • Do not breastfeed while taking this product.

  • Avoid beer, wine, and mixed drinks (alcohol) while taking this product.

  • Take extra care if you are at a high risk for infection. This includes people who have had a transplant, are on chemo, or have an autoimmune disease.

  • This product may cause you to be sleepy. Take extra care driving and doing tasks that you need to be alert for.

  • Take extra care and check with your doctor if you have:

    • Heart problems

    • Liver problems

    • Cancer

    • HIV

    • Attention-deficit/hyperactivity disorder (ADHD)

    • Mental issues, like Alzheimer disease, bipolar disorder, or schizophrenia

    • Low mood

What should I watch for?

  • Stomach pain or cramps

  • Hard stools

  • Dry mouth

  • Feeling dizzy

  • Feeling tired

  • Sensitivity to sunlight

  • Rash

When do I need to call the doctor?

  • Signs of a very bad reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat. Go to the ER right away.

  • Symptoms of too much serotonin in your body. These include irritability, restlessness, confusion, fast heartbeat, twitching, very bad sweating, very high fever, seizures, or uneven heartbeat.

  • Signs of nerve problems. These include unusual sensitivity or pain when the skin is touched; stinging pain when exposed to sunlight.

  • Very bad throwing up

  • Very bad loose stools

  • Very bad headache

  • Problems with sperm movement; difficulty having children

  • Unusually high energy, anxiety, talking a lot, difficulty sleeping, restlessness, or irritability lasting for long periods of time

  • Not able to think clearly or change in thinking

Where can I learn more?

National Center for Complementary and Integrative Health

Last Reviewed Date


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