St. John’s Wort – Actions, Uses, and Cautions

St. John’s Wort, whose botanical name is hypericum perforatum, is a perennial plant with yellow star-shaped flowers that originated in Europe, but now grows wild all over the world. It’s so common in California, for example, that efforts have been made to curb its spread; it’s called klamath weed there.

St. John’s Wort has been used for medicinal purposes since the first century, when it was recommended for sciatica, burns, and fevers. Native Americans used it for colic, nosebleeds, kidney problems, and to encourage menstruation. More recently, though, it has become popular for a completely different condition: Germany’s Commission E has approved it for the treatment of mild to moderate depression. Studies published in the British Medical Journal have also mentioned its use for this same purpose.

Research on how this popular herb works has been inconclusive. There have been studies that have shown that it can be just as effective against depression as synthetic drugs like fluoxetine (Prozac), sertraline (Zoloft), and imipramine. There are theories that its action is similar to that of monoamine oxidase inhibitors (MAOIs), but it seems to do more than MAOIs. And even though hypericin has been identified as an active ingredient, it now seems that there may be others – for example, hyperforin. The most general theory is that St. John’s Wort may increase serotonin, dopamine, and norepinephrine – brain chemicals that help us feel good.

But St. John’s Wort has other actions as well. It has also been shown to function as an anti-inflammatory and antibiotic when used topically (on the skin) for cuts, burns, and rashes. It has antiviral properties, making it useful for herpes simplex (genital herpes), shingles, and chicken pox. And newer research indicates that it may be helpful for the following:

– obesity – as an appetite suppressant

– Parkinson’s Disease and smoking cessation – as a dopamine booster

– arthritis, muscle pain, and hemorrhoids – as a pain reliever and anti-inflammatory (used topically)

– Seasonal Affective Disorder (SAD)

St. John’s Wort is fairly easy to find these days. In the United States it’s common to find bottles of the capsules and extracts in mainstream grocery stores and pharmacies as well as natural food stores. It has even been added to drinks and to some snack foods – although it’s doubtful that those would provide enough of the herb to do any good.

If you’re interested in taking St. John’s Wort for depression, there are some cautions to consider. For one thing, it has not been proven helpful with the bipolar (manic-depressive) form of depression. It’s not a good idea to use St. John’s Wort if you’re already taking synthetic antidepressants. And it’s not recommended for people taking anticonvulsants (like phenobarbital), cardiac medications (like Digoxin), drugs to stop transplant rejection (like cyclosporine), or protease inhibitors (for HIV).

Use of St. John’s Wort during pregnancy or breastfeeding has not been proven safe. And if you’re taking it internally, it’s a good idea to avoid prolonged exposure to sunlight, because it can cause your skin to become photosensitive. If you use a topical oil or salve, make sure you’re not applying it to an open wound.

St. John’s Wort is most popular these days for depression, but it has other uses. Just be sure that you use common sense when taking it.