St. John's Wort
St. John’s wort is a plant with bright yellow flowers. The flowers have been used to ease symptoms of depression and menopause. St. John’s wort has also been applied as an ointment to help promote healing in skin problems, such as scarring and psoriasis. St. John’s wort can be taken as a pill, powder, or extract. It can also be applied as an oil or made into a tea.
300 milligrams 2 to 3 times daily
What Research Shows
May Be Effective
May Not Be Effective
Unlikely to Be Effective
- Tooth pain —unlikely to relieve pain M1
Not Enough Data to Assess
- Obsessive compulsive disorder H1
- Pregnancy I1
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
It is likely safe for most adults to take St. John’s wort orally in small doses for a short time, but reactions affecting the skin, stomach, muscles, and nerves are possible. Large doses may not be safe. Not enough studies have been done to say whether it is safe to use on the skin or by mouth for a long period. Women who are pregnant or breastfeeding should not use St. John’s wort.K1-K3
Talk to your doctor about any supplements or therapy you would like to use. St. John’s wort interacts with many over the counter and prescription medications and can interfere with treatment or make conditions worse such as:
- People with cancer, diabetes, or HIV should talk to their doctors before taking St. John’s wort. It may interact with their medicines.
- People taking migraine medication should talk to their doctor before taking St. John’s Wort. It may interact with the medicine.
- St. John’s wort may be dangerous when taken with anesthetics. It may cause heart failure or coma.
- People taking heart medication should talk to their doctor before taking St. John’s wort. It may interact with the medicine.
A1. Lakhan SE, Vieira KF. Nutritional and herbal supplements for anxiety and anxiety-related disorders: systematic review. Nutr J. 2010 Oct 7;9:42.
B. Atopic Eczema
B1. Thandar Y, Gray A, et al. Topical herbal medicines for atopic eczema: a systematic review of randomized controlled trials. Br J Dermatol. 2017 Feb;176(2):330-343.
C. Attention Deficit Hyperactivity Disorder
C1. Sarris J, Kean J, et al. Complementary medicines (herbal and nutritional products) in the treatment of Attention Deficit Hyperactivity Disorder (ADHD): a systematic review of the evidence. Complement Ther Med. 2011 Aug;19(4):216-227.
D. Burning Mouth Syndrome
D1. Liu YF, Kim Y, et al. Burning mouth syndrome: a systematic review of treatments. Oral Dis. 2018 Apr;24(3):325-334.
E. Cesarean Section
E1. Samadi S, Khadivzadeh T, et al. The effect of Hypericum perforatum on the wound healing and scar of cesarean. J Altern Complement Med. 2010;16(1):113-117.
F1. Nahas R, Sheikh O. Complementary and alternative medicine for the treatment of major depressive disorder. Can Fam Physician. 2011;57(6):659-663.
F2. Sarris J, Panossian A, et al. Herbal medicine for depression, anxiety and insomnia: a review of psychopharmacology and clinical evidence. Eur Neuropsychopharmacol. 2011 Dec;21(12):841-860.
F3. Purgato M, Papola D, et al. Paroxetine versus other anti-depressive agents for depression. Cochrane Database Syst Rev. 2014 Apr 3;(4):CD006531.
F4. Apaydin EA, Maher AR, et al. A systematic review of St. John’s wort for major depressive disorder. Syst Rev. 2016;5(1):148.
F5. Seifritz E, Hatzinger M, et al. Efficacy of Hypericum extract WS (®) 5570 compared with paroxetine in patients with moderate major depressive episodes-a subgroup analysis. Int J Psychiatry Clin Pract. 2016;20(3):126-132.
F6. Ng QX, Venkatanarayanan N, et al. Clinical use of Hypericum perforatum (St John’s wort) in depression: A meta-analysis. J Affect Disord. 2017;210:211-221.
F7. Asher GN, Gartlehner G, et al. Comparative Benefits and Harms of Complementary and Alternative Medicine Therapies for Initial Treatment of Major Depressive Disorder: Systematic Review and Meta-Analysis. J Altern Complement Med. 2017 Dec;23(12):907-919.
G1. Laakmann E, Grajecki D, et al. Efficacy of Cimicifuga racemosa, Hypericum perforatum and Agnus castus in the treatment of climacteric complaints: a systematic review. Gynecol Endocrinol. 2012 Sep;28(9):703-709.
G2. Liu YR, Jiang YL, et al. Hypericum perforatum L. preparations for menopause: a meta-analysis of efficacy and safety. Climacteric. 2014;17(4):325-335.
H. Obsessive Compulsive Disorder
H1. Sarris J, Camfield D, et al. Complementary medicine, self-help, and lifestyle interventions for obsessive compulsive disorder (OCD) and the OCD spectrum: a systematic review. J Affect Disord. 2012 May;138(3):213-221.
I1. Dante G, Pedrielli G, et al. Herb remedies during pregnancy: a systematic review of controlled clinical trials. J Matern Fetal Neonatal Med. 2013 Feb;26(3):306-312.
J. Premenstrual Syndrome
J1. Dante G, Facchinetti F. Herbal treatments for alleviating premenstrual symptoms: a systematic review. J Psychosom Obstet Gynaecol. 2011 Mar;32(1):42-51.
K1. Izzo AA. Interactions between herbs and conventional drugs: overview of the clinical data. Med Princ Pract. 2012;21(5):404-428.
K2. Tsai HH, Lin HW, et al. Evaluation of documented drug interactions and contraindications associated with herbs and dietary supplements: a systematic literature review. Int J Clin Pract. 2012 Nov;66(11):1056-1078.
K3. Asher GN, Corbett AH, et al. Common Herbal Dietary Supplement-Drug Interactions. Am Fam Physician. 2017 Jul 15;96(2):101-107.
L. Smoking Cessation
L1. Hughes JR, Stead LF, et al. Antidepressants for smoking cessation. Cochrane Database Syst Rev. 2014 Jan 8;(1):CD000031.
M. Tooth Pain
M1. Raak C, Büssing A, et al. A systematic review and meta-analysis on the use of Hypericum perforatum (St. John’s Wort) for pain conditions in dental practice. Homeopathy. 2012;101(4):204-210.
Last reviewed July 2019 by EBSCO NAT Review Board Eric Hurwitz, DC Last Updated: 3/27/2020