Herbs & Supplements

Should I take it?

Rue is believed to have originated in southern Europe or northern Africa. It now grows in most parts of the world as a small evergreen bush with flat bluish-green leaves and small yellow or greenish flowers that bloom in late summer. For use in medicine and food, its leaves and young stems are gathered before rue flowers bloom. Although rue is often used as an ornamental plant in gardens or flowerbeds, its strong smell usually makes rue unpopular for use close to homes. However, the same strong smell gives either fresh rue leaves or rue oil effectiveness as an insect repellent when rubbed onto the skin of humans and animals. Sometimes, rue plants are also used as natural pesticides, planted among other bushes such as roses or raspberries to keep away insects and small animals. Some evidence suggests it may act as a natural herbicide against some other plants, as well.

Ancient Egyptians and early Greeks believed that rue taken orally could improve eyesight and it was taken commonly by medieval artists, crafters, and writers who needed good vision to perform close work. The juice of fresh rue has also been used to relieve toothaches and earaches. In Chinese medicine, rue is used to eliminate intestinal worms. Even though rue has been used historically for a number of other serious conditions, such as acute infections, heart conditions, and mental illnesses, no scientific studies currently support any of these uses.

The U.S. Food and Drug Administration (FDA) has approved rue oil as a flavoring agent. Because it is related to citrus fruits, rue oil has a flavor similar to the bitter oil in orange peels or lemon rinds. Small amounts of it may be used in cosmetics and foods. Fresh rue leaves are sometimes added to mixed salads, used in making pickles, or put into cooked dishes for a bitter taste. In Italy, rue is used to flavor grappa, a type of brandy.

Dosage and Administration

Single oral doses of over 120,000 mg (120 grams or about 4 ounces) of fresh rue or 10 mL (about 2 teaspoons) of rue oil are reported to have resulted in kidney damage, liver damage, or death.

Although taking rue by mouth is not recommended, individuals who decide to take it should be very careful to limit oral doses of dried rue to 1,000 mg (one gram) or less per day, for only a few days at a time. Fresh rue should not be taken orally.

Generally, dried rue is less likely to cause serious side effects than fresh rue because volatile rue oils are lost as the plant dries. Also called essential oils, volatile oils possess the characteristic smell and taste of the plant. They usually evaporate quickly at room temperature.

For oral use, dried rue is often brewed into a tea using one teaspoon of the dried leaves and stems of the plant and one cup (about 8 ounces) of boiling water. The water is poured over the rue, which is allowed to soak until the liquid becomes cool. The solid particles are strained out before drinking the cooled tea. Only one cup of rue tea should be used per day and rue should not be used longer than a few days at a time.

Summary

In many parts of the world, rue is taken by mouth to induce abortion or to initiate menstrual periods. It may not be particularly effective; however, and it carries the risk of damage to the kidneys or liver. Topically, rue oil may be used to treat arthritis pain, bruises, or sprains. It may also be applied to ward off insects.

Risks

Because it may cause miscarriage, rue should not be used by women who are or who may be pregnant. It should also be avoided by women who are breast-feeding and children who are under 18 years of age. The volatile oils in rue may irritate the gastrointestinal tract, possibly causing or worsening kidney, liver, or stomach conditions.

Side Effects

By mouth, rue may cause nausea, stomach pain, and vomiting. If it comes in contact with the skin, rue may cause blisters or rash. Either orally or topically, rue may make the skin more sensitive to light.

Interactions

When used with drugs that also increase the sensitivity of the skin to sunlight or artificial sun tanning light, rue may increase the chances of sunburn.

Last Revised October 19, 2007