Principal Proposed Uses
Other Proposed Uses
St. John's wort is a common perennial herb of many branches and bright yellow flowers that grows wild in much of the world. Its name derives from the herb's tendency to flower around the feast of St. John. (A wort simply means plant in Old English.) The species name perforatum derives from the watermarking of translucent dots that can be seen when the leaf is held up to the sun.
St. John's wort has a long history of use in treating emotional disorders. During the Middle Ages, St. John's wort was popular for "casting out demons." In the 1800s, the herb was classified as a nervine, or a treatment for "nervous disorders." When pharmaceutical antidepressants were invented, German researchers began to look for similar properties in St. John's wort.
What Is St. John's Wort Used for Today?
Today, St. John's wort is a widely used treatment for depression in Germany, other parts of Europe, and the United States. The evidence-base for its use approaches that of many modern prescription drugs at the time of their first approval.
Most studies of St. John's wort have evaluated individuals with major depression of mild to moderate intensity. This contradictory-sounding language indicates that the level of depression is more severe than simply feeling "blue." However, it is not as severe as the most severe forms of depression. Typical symptoms include depressed mood, lack of energy, sleep problems, anxiety, appetite disturbance, difficulty concentrating, and poor stress tolerance. Irritability can also be a sign of depression.
What Is the Scientific Evidence for St. John's Wort?
Studies of St. John's wort (and other antidepressants) use a set of questions called the Hamilton Depression Index (HAM-D). This scale rates the extent of depression, with higher numbers indicating more serious symptoms.
If the herb bothers your stomach, take it with food.
Remember that the full effect takes 4 weeks to develop. Do not give up too soon!
However, there are a number of potential safety risks with St. John's wort that should be considered. These are outlined in the following sections.
The morals of the story are as follows: if you are especially sensitive to the sun, do not exceed the recommended dose of St. John's wort, and continue to take your usual precautions against burning. If you are receiving UV treatment, do not use St. John’s wort at all; and if you apply St. John’s wort to your skin, keep that part of your body away from the sun.
Note that these proposed interactions are not purely academic: they could lead to catastrophic consequences. Indeed, St. John's wort appears to have caused several cases of heart, kidney, and liver transplant rejection by interfering with the action of cyclosporine.
Finally, some people with HIV take St. John's wort in the false belief that the herb will fight AIDS. The unintended result may be to reduce the potency of standard anti-HIV drugs.
Transitioning from Medications to St. John's Wort
If you are taking a prescription drug for mild to moderate depression, switching to St. John's wort may be a reasonable idea if you would prefer taking an herb. To avoid overlapping treatments, the safest approach is to stop taking the drug and allow it to wash out of your system before starting St. John's wort. Consult with your doctor on how much time is necessary.
However, if you are taking medication for severe depression, switching over to St. John's wort is not a good idea. The herb probably will not work well enough, and you may sink into a dangerous depression.
Interactions You Should Know About
If you are taking:
- Antidepressant drugs, including MAO inhibitors , SSRIs , and tricyclics , or possibly the drugs tramadol or sumatriptan (Imitrex): Do not take St. John's wort at the same time. Actually, you need to let the medication flush out of your system for a while (perhaps weeks, depending on the drug) before you start the herb.
- Digoxin , cyclosporine and tacrolimus, protease inhibitors or reverse transcriptase inhibitors , oral contraceptives , tricyclic antidepressants , warfarin (Coumadin) , statin drugs , theophylline , chemotherapy drugs, newer antipsychotic medications (such as olanzapine and clozapine ), anesthetics, or, indeed, any critical medication: St. John's wort might cause the drug to be less effective. Furthermore, if you are already taking St. John's wort and your physician adjusts your medication dosage to achieve proper blood levels, suddenly stopping St. John's wort could cause the level of the drug in your body to rebound to dangerously high levels.
- Medications that cause sun sensitivity such as sulfa drugs and the anti-inflammatory medication piroxicam (Feldene) , as well as omeprazole (Prilosec) or lansoprazole (Prevacid) : Keep in mind that St. John's wort might have an additive effect.
- Stimulant drugs or herbs such as Ritalin, caffeine, or ephedrine ( ephedra ): It is possible that St. John’s wort might interact adversely with them.
- Reviewer: EBSCO CAM Review Board
- Review Date: 08/2013 -
- Update Date: 08/22/2013 -