St. John’s Wort


St. John’s wort – also known as hypericum perforatum, Klamath weed, and goatweed – is a yellow-flowering plant that has been used in medicine for centuries. Historical medicinal uses of St. John’s wort include treatment for mental disorders, nerve pain, and malaria. In addition, it has been used as both a sedative and as topical treatment for wounds, burns, and insect bites. In more recent times, St. John’s wort has also been used to treat depression, anxiety, and sleep disorders.

Although substantial research suggests that St. John’s wort is safe for most people when taken orally and as directed, it can be unsafe when used in combination with certain prescription medicines. Examples of medications with which St. John’s wort interacts include birth control pills, cyclosporine (a drug that prevents the body from rejecting transplanted organs), digoxin (a drug used to treat congestive heart failure and heart rhythm abnormalities), certain drugs used to control HIV infection, certain anti-cancer drugs, anti-seizure medications such as phenytoin and phenobarbitol, and blood-thinning medications such as warfarin (Coumadin). St. John’s wort can also adversely interact with a number of antidepressants and cause potentially dangerous levels of the neurotransmitter serotonin. As such, anyone who is taking antidepressant medications should consult their doctor before also taking a St. John’s wort supplement.  (note – St. Johns Wort + Antidepressants + 5-HTP…  probably not a good idea! – consult with your doctor!)

In addition to the numerous potential drug interactions, St. John’s wort can also produce a number of side effects in individuals who use it. These include increased sensitivity to sunlight, anxiety, dry mouth, dizziness, upset stomach, diarrhea, fatigue, headache, and sexual dysfunction.

St. John’s Wort and Depression

Depression is extremely common among fibromyalgia patients. Although antidepressant medications are often the first-line treatment for many sufferers, some research suggests that St. John’s wort may be just as effective as certain prescription antidepressants. Therefore, St. John’s wort may be of use to fibromyalgia patients as a potential source of therapy for depression.

St. John’s wort has been shown in numerous studies to improve mood, decrease anxiety, and improve depression-related sleep disturbances in individuals with both mild and severe depression. In fact, the American College of Physicians – American Society of Internal Medicine suggest in their clinical guidelines that St. John’s wort can be considered an option for the short-term treatment of mild depression (Snow et al., 2000). It is important to note, however, that St. John’s wort has not been shown to be more effective than conventional antidepressant therapy. In addition, since it interferes with a number of prescription medications – including some antidepressants – it may not be the best choice of treatment for everyone. For those suffering depression who desire a non-pharmaceutical options however St. Johns Wort may be a good first choice.

Several studies have demonstrated that St. John’s wort is likely as effective as certain tricyclic antidepressants, including imipramine (Tofranil) (Kim et al., 1999; Linde et al., 1996; Philipp et al., 1999). A 1999 study by Kim et al. analyzed findings from a number of previously-conducted studies in which St. John’s wort was compared to both tricyclic antidepressants and placebo (sugar pill). The analysis found that St. John’s wort was 1.5 times more likely to produce an antidepressant effect than placebo (sugar pill), and that the magnitude of its impact on depression-related symptoms was roughly equal to that of the antidepressant medications (Kim et al., 1999). An earlier analysis of 23 studies produced similar findings (Linde et al., 1996). A study published in 1999 compared the use of St. John’s wort and imipramine over an eight week course of treatment in 263 patients with moderate depression. This double-blind, randomized, placebo-controlled trial (the “gold standard” for research study design when attempting to compare the efficacy of two or more treatments) found that those patients who were treated with either St. John’s wort or imipramine showed significant improvement in both depression and quality of life measures, when compared to those who received a placebo. In addition, those patients who received St. John’s wort experienced fewer side effects than those treated with imipramine (Philipp et al., 1999).

In addition, several studies have compared the effectiveness of St. John’s wort and a number of popular selective serotonin reuptake inhibitors, or SSRIs, including Prozac, Zoloft, and Paxil. These findings are not surprising in light of the fact that research suggests the antidepressant properties of St. John’s wort may be due to its ability to impact serotonin levels in the body (Calapai et al., 2001). These studies all found that St. John’s wort was likely as effective as the comparison SSRI in treating mild to moderate depression.

In a randomized, controlled trial comparing St. John’s wort to fluoxetine (Prozac) in 149 elderly patients (129 of whom were female), Harrer et al. found that the efficacy of both fluoxetine and St. John’s wort were equivalent in significantly improving symptoms associated with both mild and moderate depression (Harrer et al., 1999). These findings must be taken in context however, as the study was conducted among elderly depression patients. As such, the findings may not be applicable to younger individuals. Schrader (2000) and colleagues also compared fluoxetine and St. John’s wort in 240 patients with mild to moderate depression. Not only did they find that the two treatments were equivalent in their ability to improve depression-related measures, but they also found that St. John’s wort was significantly better tolerated, with substantially fewer side effects. Brenner et al. (2000) compared St. John’s wort and sertraline (Zoloft) in a small, double-blind, randomized study. The 30 patients enrolled in this study (19 of whom were female), were treated with either St. John’s wort or sertraline for a period of six weeks. Depression-related symptom severity was significantly improved for both groups at the end of the treatment period. The findings of this study should be interpreted with caution, however, due to the small sample size. Finally, a more recent study by Szegedi et al. (2005) investigated the effectiveness of St. John’s wort to treat depression in yet another double-blind, randomized controlled trial. The researchers compared the effectiveness of St. John’s wort to another antidepressant, paroxetine (Paxil) in 251 adults with major depression. Patients were treated with either paroxetine or St. John’s wort over a period of six weeks. At the end of the study, results showed that St. John’s wort was as effective as Paxil in the treatment of moderate to severe major depression. In addition, the researchers also found that St. John’s wort had fewer side effects and was better tolerated by patients than paroxetine.

Learn more about treating fibromyalgia HERE.



1.        Kim HL, Streltzer J, Goebert D. St. John’s wort for depression: A meta analysis of well-defined clinical trials. J Nerv Ment Dis. 1999;187:532-539.

2.        Linde K, Ramirez G, Mulrow CD, et al. St. John’s wort for depression: an overview and meta-analysis of randomized clinical trials. BMJ. 1996;313:253-258.

3.        Philipp M, Kohnen R, Hiller KO. Hypericum extract versus imipramine or placebo in patients with moderate depression: randomized mulicentre study of treatment for eight weeks. BMJ. 1999;319:1534-1539.

4.        Harrer G, Schmidt U, Kuhn U, Biller A. Comparison of equivalence between the St. John’s wort extract LoHyp-57 and fluoxetine. Arzneimittelforschung. 1999;49:289-296.

5.        Schrader E. Equivalence of St. John’s wort extract (Ze 117) and fluoxetine: a randomized, controlled study in mild-moderate d

epression. Int Clin Psychopharmacol. 2000;15:61-68.

6.        Brenner R, Azbel V, Madhusoodanan S, et al. Comparison of an extract of Hypericum (LI 160) and sertraline in the treatment of depression: A double-blind, randomized pilot study. Clin Ther. 2000;22:411-419.

7.        Szegedi A, Kohnen R, Dienel A, Kieser M. Acute treatment of moderate to severe depression with hypericum extract WS 5570 (St John’s wort): randomised controlled double blind non-inferiority trial versus paroxetine. BMJ. 2005;330:503.

8.        Snow V, Lascher S, Mottur-Pilson C. Pharmacologic treatment of acute major depression and dysthymia. Ann Intern Med. 2000;132:738-742.

Calapai G, Crupi A, Firenzuoli F, et al. Serotonin, norepinephrine and dopamine involvement in the antidepressant action of hypericum perforatum. Pharmacopsychiatry. 2001;34:45-49.

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