Rue (Ruta graveolens) is a strong-smelling, bitter herb used for centuries in folk medicine to treat pain, digestive problems, menstrual irregularities, and skin conditions. It also has a long history as a culinary herb in Mediterranean and Ethiopian cooking, though only in very small amounts. Today, rue remains popular in traditional medicine systems around the world, and lab studies have confirmed several of its biological effects. However, it carries real safety risks that anyone handling or consuming it should understand.
Traditional Medicinal Uses
Rue has one of the longest resumes of any medicinal herb. It appears in the writings of Hippocrates for treating lung and gynecological conditions, and it has been a staple in Indian traditional medicine systems including Ayurveda, Unani, and Siddha for centuries. In Chinese medicine, rue is classified as slightly bitter, pungent, and cooling, and it has been used to treat fevers, headaches, toothaches, bruises, sprains, eczema, and snake bites.
Across Latin America, the primary traditional use of rue is to stimulate menstrual flow by activating the muscles of the uterus. This same property made it one of the most well-known folk abortifacients in history. In Indian tradition, the leaves have been applied externally for sciatica, headache, muscular chest pain, bronchitis, and arthritis.
Rue tea and infusions have also been widely used for eye complaints. Traditional practitioners believe that steeping the herb and using the liquid as a wash can relieve tired, strained eyes and even improve vision. For digestive issues like gas, bloating, and colic, small amounts of rue or diluted rue oil mixed with water and sugar have been a common folk remedy.
What Science Shows About Rue’s Effects
Animal studies have backed up several of rue’s traditional claims. In one study, a leaf extract reduced pain responses in mice by 54% at a moderate dose, and higher doses significantly delayed pain reactions to heat. The same research found measurable anti-inflammatory and fever-reducing effects in rats, supporting its long use for pain, swelling, and fever.
Rue also shows anticonvulsant properties. In mice given a chemical that triggers seizures, rue extract delayed the onset of both mild and severe seizure types in a dose-dependent pattern and reduced seizure-related death rates. This aligns with its traditional use in Iranian medicine as a treatment for epilepsy, where it has been prescribed for centuries under the name “Sodab.” Rue oil has also been described as antispasmodic, meaning it may help relax involuntary muscle contractions in the gut and elsewhere.
It’s worth noting that these findings come from animal and lab research. Human clinical trials on rue are extremely limited, so the effective and safe doses for people remain unclear.
Culinary Uses
In cooking, rue is used sparingly as a bitter flavoring agent. Its taste is intensely bitter and slightly pungent, which means a little goes a long way. In Ethiopian cuisine, fresh rue leaves are sometimes added to coffee or used in spice blends. In parts of Italy, rue has traditionally flavored grappa and certain cheeses. Some Mediterranean recipes call for a few leaves in salads or egg dishes.
The U.S. FDA lists rue oil as Generally Recognized as Safe (GRAS) when used as a flavoring agent, under regulation 21 CFR 184.1699. This classification applies specifically to the tiny amounts used in food flavoring, not to medicinal doses of the whole herb or concentrated extracts.
Skin Reactions and Phototoxicity
One of rue’s most important risks is phytophotodermatitis, a skin reaction triggered when plant chemicals meet ultraviolet light. Rue’s stems and leaves contain compounds called furanocoumarins (including psoralen, bergapten, and several others) that absorb UV radiation and damage skin cells. If you handle fresh rue and then go into sunlight, the result can range from mild redness to severe blistering and peeling that looks like a chemical burn.
This reaction is not an allergy. It happens to anyone whose skin contacts enough of these compounds and then gets sun exposure. Gardeners are the most common victims. If you grow or handle rue, wearing gloves and long sleeves is essential, and you should wash any exposed skin thoroughly before going outdoors.
Reproductive Risks
Rue has historically been listed among the most potent herbal abortifacients alongside pennyroyal, tansy, and savin. Its traditional use to stimulate menstruation and induce miscarriage is well documented across multiple cultures. Interestingly, some modern research on isolated human uterine tissue has not replicated the strong uterine-stimulating effect that folklore describes, and controlled animal studies have not consistently shown fetal death. Still, the traditional evidence is widespread enough that pregnant women are universally advised to avoid rue in any form.
Other Safety Concerns
Rue taken internally at medicinal doses (as opposed to the trace amounts used in cooking) can cause nausea, vomiting, and stomach irritation. Higher doses pose more serious risks. The line between a “therapeutic” amount and a toxic one is narrow and poorly defined in humans, which is a core reason rue’s use in developed countries has declined sharply.
The concentrated essential oil is considerably more potent than teas or leaf preparations. Because the active compounds are so concentrated in the oil, even small amounts taken internally can cause intense gastrointestinal distress. If you’re considering using rue for any health purpose, the lack of established safe dosing in humans is the most important thing to keep in mind.