One man's weed is another man's flower, and so it is with St. John's wort. But this flower/weed is special because it has been a panacea in the herbal doctor's medicine chest since ancient Greece. It is one of the most commonly purchased herbal products in the United States. Does it live up to 5 centuries of hype?

The answer is, “pretty much.”

Research suggests that St. John's wort may help relieve physical and emotional symptoms of premenstrual syndrome in some women, including cramps, irritability, food cravings, and breast tenderness. One study reported a 50 percent reduction in the severity of symptoms.
Evidence suggests that St. John's wort, combined with black cohosh, will improve mood and anxiety during menopause.
St. John's wort has improved mood in people with seasonal affective disorder, a type of depression that occurs during the winter months because of lack of sunlight. The herbal treatment works even better when combined with phototherapy.
The antibacterial properties of St. John's wort have been proven effective against eczema, wounds, minor burns, and even hemorrhoids.

But the big dragon that so many look to St. John's wort to slay is depression. Here, it is not nearly the wonder herb that many people think. Studies indicate that the flower is effective in treating mild depression, but no better than a placebo for moderate or severe depression.

St. John's wort is not all hearts and flowers, however. Side effects from the herb may include stomach upset, hives or other skin rashes, fatigue, restlessness, headache, dry mouth, and feelings of dizziness or mental confusion. St. John's wort can also make the skin overly sensitive to sunlight, a condition known as photodermatitis. Other known issues include making the symptoms of attention deficit disorder worse, and even preventing pregnancy. Be sure to check with your physician before embarking upon a regimen of this herb.

Another concern, one that we have with all herbal and so-called “natural” medicines, is that St. John's wort is not regulated by the Food and Drug Administration. You have no real safeguard that you are dosing with what you think you are dosing. Note, too, that St. John's wort has a whole host of interactions with other popular drugs – so many that France has banned the use of St. John's wort in all products, and warnings of herb-drug interactions are listed in Japan, the UK and Canada, but not the US.

Finally... what's with that name? The flower gets its moniker from St. John the Baptist, whose birthday is celebrated on June 24 – usually the same day that this botanical is in full bloom.