St. John's wort (
Hypericum perforatum) is an herbal supplement often used to treat
depression, although it is sometimes used for other conditions as well. It is a yellow flowering plant that is native to Europe.
St. John's wort can work in several different ways, as it contains many different active compounds. In some ways, it works similarly to selective serotonin reuptake inhibitor (
SSRI)
antidepressants. This means that it may prevent nerve cells from reabsorbing serotonin (a naturally occurring neurotransmitter brain chemical). By preventing the reabsorption of serotonin, St. John's wort increases the amount of serotonin that is available and active in the brain. This may help relieve some of the
symptoms of depression.
It may also affect several naturally occurring chemicals in the body. It is not entirely clear how these other effects contribute to the properties of St. John's wort.
Is St. John's Wort Effective?
It is not clear if St.
John's wort is really effective at treating depression. There is quite a bit of evidence suggesting that it is effective for
depression treatment. However, a few important studies have shown that it is no more effective than a placebo (a "sugar pill" that does not contain any active ingredients). Although early research suggests that St. John's wort may be useful for a few other conditions, more research is necessary to confirm this.
Because St. John's wort is regulated as a
dietary supplement, rather than a drug, less information is available about how to safely and effectively take it. The general dosing information available is based on clinical studies and years of experience with this supplement.
Side Effects of St. John's Wort
Many people believe that natural products, such as St. John's wort, do not have any side effects. However, many natural products cause side effects, some of which can be quite serious. St. John's wort can cause side effects such as:
(Click St. John's Wort Side Effects to learn more, including potentially serious side effects that you should report immediately to your healthcare provider.)
This supplement may interact with several medications
(see St. John's Wort Drug Interactions). For many people, the risk of drug interactions due to St. John's wort is not worth the slight benefits that may be obtained from using the supplement.
St. John's wort appears to be safe when taken at reasonable doses. However, some people are more likely to experience problems than others. Talk with your healthcare provider prior to taking St. John's wort if you have:
Also, let your healthcare provider know if you are:
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
What If I Take an Overdose?
It is not known what exactly to expect from an overdose with St. John's wort, although it is reasonable to expect that any of the usual side effects could occur, but perhaps more severely.
Seizures have also been reported due to an overdose with St. John's wort.
If you think you may have taken too much St. John's wort, seek immediate medical attention.
How Should St. John's Wort Be Stored?
Refer to the label of your individual product for information on how best to store this product. Keep St. John's wort and all other medications and supplements out of the reach of children.
