Ruta graveolens is a strongly aromatic evergreen herb, sometimes growing into a small shrub, that belongs to the Rutaceae (citrus) family. You may know it by its common names: rue, common rue, or herb-of-grace. Native to the Mediterranean region, it has been cultivated for centuries across the world as a medicinal, culinary, and ornamental plant. It contains over 230 identified chemical compounds, some of which are biologically potent and potentially dangerous.
What the Plant Looks and Smells Like
Rue is a hairless, bluish-green perennial that typically grows one to three feet tall. Its leaves are fleshy, deeply divided, and dotted with tiny oil glands you can see when you hold a leaf up to the light. Those glands are responsible for the plant’s strong, distinctive smell, which most people describe as bitter and slightly musky. Some find it pleasant in small doses; others find it overwhelming.
The flowers are small and yellow-green with smooth, slightly wavy petals. This is one way to distinguish Ruta graveolens from a closely related species, Ruta chalepensis, which has fringed or hairy petal edges. Rue thrives in dry, rocky, well-drained soil and tolerates poor conditions, which is part of why it spread so easily from its Mediterranean origins to gardens worldwide.
Key Active Compounds
Phytochemical analysis has identified 231 compounds in rue, spanning several major groups. The most abundant non-volatile components are alkaloids, particularly acridone and quinoline types. These compounds contribute to the plant’s biological activity, including its effects on the nervous system and smooth muscle tissue.
Rue also contains furanocoumarins, a class of compounds that includes psoralen. These are the chemicals behind the plant’s most well-known hazard: severe skin reactions triggered by sunlight. The flavonoid rutin, first isolated from this very plant (and named after it), is another notable compound. Rutin acts as an antioxidant and has been shown in lab studies to inhibit certain enzyme activity by 27 to 52 percent. Volatile oils round out the chemical profile and account for the plant’s intense aroma.
Traditional and Folk Medicine Uses
Rue has one of the longest recorded histories of any medicinal herb. Ancient Greek and Roman texts reference it for improving eyesight, easing digestive complaints, and repelling insects. In traditional medicine systems across Europe, the Middle East, and South America, rue tea or poultices have been used for headaches, muscle spasms, menstrual irregularities, and joint pain. In Hindi-speaking regions, the plant goes by “Sadab” or “Satab” and has a parallel tradition of folk use.
One of its most significant historical applications was as an abortifacient. Rue tea has been used for centuries to induce abortion, and case reports from poison control centers confirm that this practice continues today, particularly in parts of South America. The exact mechanism is not fully understood, but it likely involves either blocking progesterone (which sustains early pregnancy) or stimulating uterine contractions, or both. This use carries serious medical risks, which are covered in the safety section below.
Homeopathic Preparations
In homeopathy, Ruta graveolens (usually labeled as “Ruta grav” or “Ruta 6C”) is one of the more commonly used remedies. It is marketed primarily for eye strain relief, particularly the fatigue, burning, and tired-eye feeling that comes from prolonged computer use, artificial lighting, or other visually demanding tasks. It is also traditionally recommended by homeopathic practitioners for injuries involving tendons, ligaments, and the periosteum (the tissue covering bones). These preparations use extremely diluted forms of the plant.
Culinary Use and Regulatory Status
Rue has a bitter, pungent flavor that is used sparingly in some Mediterranean and Ethiopian cuisines. Small amounts of fresh leaves are occasionally added to salads, egg dishes, and cheese. In Italy, a sprig of rue is the traditional garnish placed inside bottles of grappa, the grape-based spirit.
The U.S. Food and Drug Administration lists rue oil (from Ruta graveolens) as a permitted flavoring agent under 21 CFR 184.1699, and it holds GRAS (Generally Recognized as Safe) status specifically for that limited use. This designation applies to the tiny quantities used in commercial food flavoring, not to the plant consumed in larger medicinal doses.
Skin Reactions and Phototoxicity
The most common adverse effect of handling rue is phytophotodermatitis, a skin reaction caused by furanocoumarins like psoralen. Here is how it works: the plant’s sap contacts your skin, and when that skin is then exposed to ultraviolet A light from the sun, a chemical reaction causes inflammation, redness, and blistering that can look similar to a chemical burn. The reaction is photoirritant, not allergic, meaning it can happen to anyone regardless of skin sensitivity. It does not require prior exposure or sensitization.
Burns from rue can be severe enough to leave lasting discoloration on the skin. Gardeners are the most commonly affected group, especially those who prune or handle the plant on sunny days without gloves and long sleeves. Rue should not be used as a natural insect repellent on skin, despite folk recommendations to do so.
Serious Toxicity Risks
When consumed in large quantities, particularly as a concentrated tea, rue poses significant internal toxicity risks. Data from a South American poison control center found that people who ingested rue (often in attempts at self-managed abortion) showed a higher incidence of liver damage, kidney damage, and blood abnormalities compared to baseline. Traditional medicine texts themselves have long cautioned against higher doses.
Rue is considered unsafe during pregnancy at any dose beyond trace culinary amounts. The compounds that stimulate uterine contraction do not come with a predictable dose-response curve, meaning there is no reliably “safe” amount for inducing an intended effect without risking organ damage. The gap between a dose that does nothing and a dose that causes serious harm is narrow and unpredictable.
Growing Rue at Home
Despite its toxicity risks, rue remains a popular garden plant. It is drought-tolerant, deer-resistant, and attracts swallowtail butterflies, whose caterpillars feed on the leaves. It grows well in USDA hardiness zones 4 through 9 and prefers full sun with lean, well-drained soil. Overwatering and rich soil actually reduce the plant’s vigor and oil production.
If you grow rue, wear gloves and long sleeves when pruning or harvesting, and avoid doing so on bright, sunny days. Wash any skin that contacts the sap immediately with soap and water before sun exposure. Keep the plant clearly labeled if children or pets have access to the garden, as ingestion of even moderate amounts of leaves can cause nausea, vomiting, and abdominal pain.