Rue (Ruta graveolens) is a strongly aromatic, shrub-like plant native to the Mediterranean that has been used for centuries as a digestive aid, a pest repellent in gardens, a flavoring agent in food and spirits, and a traditional remedy for conditions ranging from menstrual irregularity to nervous system complaints. It contains a potent mix of bioactive compounds, and while many of its traditional uses have some scientific backing, rue also carries real risks that are worth understanding before you grow it, handle it, or consume it in any form.
Traditional Medicinal Uses
Rue has an unusually broad history in folk medicine. In traditional Indian and Persian systems, it was primarily used to settle the stomach, manage nerve-related complaints, and regulate the menstrual cycle. Across Latin America, its most common medicinal role has been stimulating menstrual flow. In Europe, it was applied to conditions as varied as colic, flatulence, headache, anxiety, epilepsy, and vertigo. Ethnopharmacological surveys have documented its use in more than 15 countries, spanning respiratory, urinary, gastrointestinal, and nervous system complaints.
The Romans treated rue much the way we treat parsley: as a kitchen staple with perceived health benefits. It was considered both food and medicine, a dual role it maintained well into the modern era in parts of southern Europe, Latin America, and South Asia.
Active Compounds in Rue
Rue’s effects come from a dense mix of plant chemicals. The most notable include rutin (a flavonoid with anti-inflammatory properties), furanocoumarins like bergapten and xanthotoxin (which make the plant photosensitizing), and several alkaloids. It also produces essential oils containing compounds like methyl-nonyl-ketone, along with terpenes such as pinene and limonene. This chemical complexity is why rue has so many different traditional uses, and also why it can be dangerous in concentrated doses.
Anti-Inflammatory and Antimicrobial Properties
Lab studies have shown that rue extract significantly reduces the production of nitric oxide, a key inflammatory signaling molecule, in immune cells exposed to bacterial toxins. This inhibition happens at the genetic level: the extract suppresses both the gene responsible for nitric oxide production and the gene for COX-2, an enzyme involved in pain and inflammation (the same enzyme targeted by common over-the-counter painkillers like ibuprofen). Rutin alone accounts for some of this effect, but the whole plant extract outperforms rutin on its own, suggesting that multiple compounds work together.
Rue essential oils have also been tested against bacterial and fungal strains, with results supporting the traditional use of the plant as an antimicrobial agent. One particularly striking lab finding showed that rue compounds selectively damaged an antiapoptotic protein in human brain cancer cells without affecting normal immune cells, essentially making cancer cells more vulnerable to death while leaving healthy cells alone. These are laboratory results, not clinical treatments, but they help explain why the plant has attracted ongoing scientific interest.
Nervous System Effects
Several traditional uses of rue relate to the nervous system, and animal studies provide some support. In mice, an ethanol extract of a closely related species (Ruta chalepensis) delayed the onset of chemically induced seizures and reduced their severity in a dose-dependent way. The same extract prolonged sleep time when combined with a sedative, reduced anxiety-related behavior, and decreased pain responses. These findings point to a broad depressant effect on the central nervous system, which aligns with centuries of folk use for epilepsy, anxiety, hysteria, and vertigo.
Garden Pest Repellent
One of rue’s most practical modern uses is in the garden. Its strong aroma and toxic compounds naturally repel Japanese beetles and ants, making it a popular companion plant for roses. Japanese beetles are notorious for destroying both leaves and blossoms, and positioning rue plants around the perimeter of rose beds or interspersed among the bushes creates a diffused chemical barrier. If you’re looking for a low-maintenance, chemical-free way to protect ornamental plants, rue is one of the more effective options. It’s a hardy perennial that thrives in poor, well-drained soil with full sun.
Culinary and Beverage Uses
Rue has a long history as a food ingredient, though its bitter, pungent flavor means a little goes a long way. Ancient Romans pickled bunches of it in brine, used the leaves and seeds as seasoning in meat, poultry, and fish sauces, and added it to salads and olive brines. Eggs and rue were a common garnish for salt-cured fish. During Roman elections in 198 B.C., honeyed wine spiced with rue was distributed to the public as a celebratory drink.
Today, the most widely available rue-flavored product is grappa alla ruta, an Italian brandy infused with a sprig of the herb, sold in supermarkets throughout Italy. Rue oil has FDA status as a flavoring agent (listed under 21 CFR 184.1699), meaning it is permitted in small quantities in food. The key word is small: the amounts used in flavoring are far below the thresholds associated with toxicity.
Skin Reactions and Sun Sensitivity
Rue’s furanocoumarins are fat-soluble compounds that penetrate the skin readily, especially when it’s damp or humid. Once absorbed, they are activated by UVA radiation from sunlight, generating reactive oxygen species that damage skin, blood vessel, and deeper tissue cells. This reaction, called phytophotodermatitis, can produce painful blistering, redness, and long-lasting dark marks on the skin. It can appear within hours of sun exposure after handling the plant or applying a concentrated infusion. One published case involved a patient prescribed rue infusion for fibromyalgia who developed severe blistering after going outdoors.
If you grow rue or handle it in the garden, wear gloves and long sleeves. Avoid touching the plant on sunny days or washing your skin promptly afterward.
Serious Risks and Toxicity
Rue’s most dangerous traditional use is as an abortifacient. Across Latin America, it has been the most commonly ingested herbal preparation for inducing abortion. In animal studies, it caused embryo damage and fetal death when given orally to pregnant mice. In humans, it reportedly causes abortion within a day of consumption, but it can also trigger severe vomiting, liver damage, anemia, tremors, respiratory distress, and in severe cases, death. Life-threatening organ failure has been documented. The National Capital Poison Center explicitly states that this use is not approved or recommended.
Even outside of pregnancy, concentrated internal use of rue poses risks. Therapeutic doses have been associated with depression, sleep disturbances, fatigue, dizziness, and cramps. The sap from fresh leaves can cause gastrointestinal irritation, fainting, a weak pulse, and a swollen tongue. The University of Texas at El Paso’s herbal safety program notes that modern scientific herbalism considers internal use of rue obsolete due to its toxicity. It should not be given internally to children, elderly individuals, or anyone with heart or kidney problems.
The gap between a potentially beneficial dose and a harmful one is narrow with rue. Its value is best appreciated in the garden, in trace amounts as a culinary flavoring, or as a subject of ongoing pharmacological research rather than as a self-administered herbal remedy.