Rue

Ruta graveolens

Common & Folk Names

• Common Rue
• Herb of Grace
• German Rue
• Garden Rue
• Herbygrass

Plant Family

Rutaceae

Geographic Location

Native to the Mediterranean region, particularly the Balkan Peninsula and southern Europe. Now naturalised in some temperate regions and cultivated in herb gardens worldwide. Thrives in warm, dry Mediterranean climates with abundant sunshine.

Habitat

Naturally grows in rocky, dry hillsides, poor soils, and sunny locations in Mediterranean regions. Prefers well-draining soil and full sun. Tolerates drought and poor soil conditions once established. Found from sea level to moderate elevations.

Growing Conditions

Sun: Full sun essential; requires at least 6-8 hours direct sunlight daily

Soil: Very well-draining, light, sandy or gravelly soil; tolerates poor soil; pH 6.0-8.0 (slightly acidic to alkaline); intolerant of waterlogging

Propagation: Grow from seed sown in spring (germinates readily) or softwood cuttings in summer

Care: Water sparingly once established; drought-tolerant; requires minimal fertilization; prune to maintain shape; generally pest-free (strong scent deters pests); can become woody with age

NZ Planting Calendar

Sowing (seed): Spring (September-November); sow seeds on surface or lightly cover

Propagation (cuttings): Take softwood cuttings in summer (December-February)

Planting: Spring (September-November) or autumn (March-May)

Growth: Perennial subshrub; evergreen to semi-evergreen; grows 60-90cm tall; attractive blue-green deeply divided foliage

Flowering: Summer (December-February in NZ) with small yellow flowers

Harvest: Aerial parts (leaves and flowering tops) harvested during flowering for maximum potency

Note: Grows well in warmer, drier NZ regions (Hawke’s Bay, Marlborough, Canterbury, Central Otago); may struggle in very wet, humid areas; ornamental plant with distinctive blue-green foliage; strong, unpleasant scent; historically grown in herb gardens but medicinal use has declined dramatically due to toxicity concerns; 

Harvesting Guidelines

If harvesting must occur (professional use only):

• Wear gloves and long sleeves—skin contact causes photodermatitis
• Harvest on cloudy days or in evening to reduce photosensitivity risk
• Never harvest if planning sun exposure within 24-48 hours
• Avoid skin contact with plant sap
• Wash thoroughly after handling

The strong, acrid scent is characteristic. Properly dried rue retains blue-green colour and pungent smell.

Parts Used

• Aerial parts (leaves and flowering tops)
• NOTE: Historical use only; modern use strongly discouraged

Constituents & their Actions

Rue’s biological activity arises from furanocoumarins, alkaloids, essential oils, and other compounds that provide toxic effects alongside historical therapeutic applications.

Furanocoumarins (Including Bergapten and Xanthotoxin):

These compounds are responsible for rue’s severe photosensitivity reactions.

The main actions of furanocoumarins are:

• Cause severe photodermatitis (skin burns and blistering in sunlight)
• Demonstrate antimicrobial activity
• TOXIC EFFECTS: Severe skin reactions, potential DNA damage
• Concentration increases with plant maturity and sun exposure

Alkaloids (Including Rutacridone and Others):

Various alkaloids contributing to toxicity and historical therapeutic effects.

The main actions of alkaloids are:

• Provide uterine-stimulating effects (emmenagogue—promoting menstruation)
• Demonstrate antispasmodic properties
• TOXIC EFFECTS: Can cause abortion, liver toxicity, kidney damage
• Contribute to overall toxic profile

Essential Oil (0.2-0.7%):

Volatile compounds including methyl nonyl ketone and others.

The main actions of essential oil are:

• Provide the characteristic strong, unpleasant scent
• Demonstrate antimicrobial activity
• Contribute to skin irritation
• TOXIC in concentrated form

Rutin and Other Flavonoids:

Named after rue, rutin is a bioflavonoid with various effects.

The main actions of flavonoids are:

• Strengthen capillaries and blood vessels
• Provide antioxidant effects
• Support vascular health
• NOTE: Rutin can be obtained from safer sources (buckwheat, etc.)

Actions with Mechanisms

Antispasmodic (Historical): Alkaloids provide antispasmodic effects on smooth muscle, historically used for digestive cramping and menstrual cramps. However, the toxic effects far outweigh any antispasmodic benefits. Safer antispasmodics exist.

Antimicrobial: Furanocoumarins and essential oil demonstrate antimicrobial activity against various bacteria and fungi. However, the photodermatitis risk makes topical antimicrobial use dangerous, and internal use carries severe toxicity risks.

Vascular Support (Rutin): Rutin strengthens capillaries, supports vascular health, and demonstrates anti-inflammatory effects. However, rutin is available from much safer sources (buckwheat, citrus, etc.) without rue’s toxicity.

Main Use

Historical uses (for educational context only):

• Menstrual regulation and abortion (extremely dangerous)
• Digestive complaints and cramping
• Eye problems (traditionally, though risking further eye damage)
• Parasites and intestinal worms
• Fever and infections
• Vascular support

All of these applications have safer, more effective alternatives:

• For menstrual support: Vitex, cramp bark, raspberry leaf
• For digestive issues: Gentler bitters like dandelion, gentian
• For vascular support: Rutin from buckwheat, gotu kola, horse chestnut
• For parasites: Other anthelmintics under professional guidance
• For infections: Numerous safer antimicrobials

The risks of rue (photodermatitis, abortion, liver/kidney toxicity, poisoning) far outweigh any potential benefits.

Preparations

Historical preparations (DO NOT PREPARE OR USE):

• Infusion: 1 teaspoon dried herb per cup (extremely bitter, toxic)
• Tincture: 1:5 in 40% alcohol (toxic)
• Topical: Fresh leaves or infused oil (causes severe photodermatitis)

Dosage

Historical doses (for toxicological reference only, NOT for use):

• Traditional herbals listed 0.5-1g dried herb as “dose”
• Even these small amounts caused adverse effects in many users
• Larger amounts (deliberately taken for abortion) caused severe poisoning and death

Modern recommendation: ZERO dose. Do not use rue medicinally.

Safety & Drug Interactions

Scientific Evidence

Photodermatitis: Extensively documented in medical literature. Furanocoumarins cause phototoxic reactions well-characterized in research. Case reports of severe burns from rue contact are numerous.

Abortifacient Effects: Research confirms uterine-stimulating effects and documents cases of attempted abortion with rue resulting in severe toxicity, hemorrhage, and maternal death without reliable pregnancy termination.

Toxicity: Case reports and toxicological studies document liver damage, kidney damage, and serious adverse effects from rue consumption.

Rutin: Research validates vascular benefits of rutin, but this doesn’t justify using toxic rue when rutin is available from safe sources.

Western Energetics

Historical perspective (not recommendation for use):

Temperature: Warming

Moisture: Drying

Tissue State: Historically used for cold, damp, atonic conditions, particularly reproductive system

Modern energetic assessment: Irrelevant because rue should not be used medicinally regardless of energetic indications.

Taste

Intensely Bitter: Overwhelmingly bitter taste

Acrid/Burning: Harsh, burning sensation

Unpleasant: The taste is notably unpleasant and off-putting

Pungent: Sharp, pungent quality

Plant Lore

Rue has extensive history in European herbalism and folklore, though this history is increasingly overshadowed by modern understanding of toxicity.

The name “herb of grace” comes from rue’s use in Christian religious ceremonies for sprinkling holy water (aspergillum made from rue stems). This religious association gave rue symbolic significance beyond medicinal use.

In ancient Greece and Rome, rue was considered protective against poison, evil eye, and disease. Pliny the Elder and Dioscorides documented medicinal uses. However, ancient medicine lacked understanding of dose-response relationships and toxicity.

Medieval herbalism valued rue for numerous conditions, incorporating it into complex formulas and preparations. The strong scent was believed to ward off plague and disease (actually, the scent just masked bad smells—rue provided no protection).

Shakespeare mentions rue in Hamlet (“There’s rue for you; and here’s some for me: we may call it herb-grace o’ Sundays”) and Richard III, referencing both the plant and “rue” meaning regret/sorrow—apt given the harm rue has caused.

Folk traditions include rue for protection against witchcraft, evil eye, and misfortune. Sprigs were hung in homes, carried in pockets, or worn as amulets. These superstitious uses contributed to rue’s cultivation despite limited therapeutic value.

The use of rue for abortion is ancient and tragically continues in some communities. This application is extremely dangerous—rue causes severe maternal toxicity and unreliable pregnancy termination. Many women have died or suffered permanent damage from rue abortions. This is NOT a safe method and is potentially fatal.

Artists and engravers historically believed rue improved eyesight (Pliny mentions this). However, rue applied to eyes can cause serious damage. This “eyebright” use is dangerous and unfounded.

The discovery of rutin (named after rue) in the 1930’s suggested therapeutic value. However, rutin is available from much safer sources, eliminating any justification for using toxic rue.

Modern herbalism has largely abandoned rue due to toxicity and availability of safer alternatives. Most contemporary herbals either omit rue entirely or include it with strong warnings against use.

Some cultures maintain traditional rue use despite toxicity risks. Education about rue’s dangers and safer alternatives is essential public health work.

Additional Information

Why Rue Should Not Be Used:

1. Severe photodermatitis risk from skin contact—even brief exposure causes serious burns
2. No safe internal dose—toxicity varies unpredictably between individuals
3. Abortifacient effects are dangerous—causes maternal toxicity and unreliable pregnancy termination
4. Hepatotoxicity and nephrotoxicity—damages liver and kidneys
5. Safer alternatives exist for every traditional application
6. Risk-benefit analysis is clear: Risks are severe and certain; benefits are questionable and replaceable

Rue in Gardens: Some people grow rue as ornamental for its attractive blue-green foliage. If growing ornamentally:

• Wear gloves when handling
• Prune on cloudy days or evenings
• Wash thoroughly after any contact
• Avoid sun exposure for 24-48 hours after handling
• Keep away from children and pets
• Consider whether ornamental value justifies risk

Historical vs. Modern Perspective: Historical use of rue reflects limited understanding of toxicology. Traditional medicine lacked:

• Understanding of photodermatitis mechanisms
• Ability to measure toxic constituents
• Knowledge of safer alternatives
• Systematic adverse event reporting

Modern herbalism has evolved beyond rue due to better understanding and better options.

If You Encounter Rue Use: In some communities, rue continues to be used traditionally. If you encounter someone using rue:

• Educate about risks compassionately
• Provide information about safer alternatives
• If used for abortion, emphasise danger and provide access to safe, legal reproductive healthcare
• If skin exposure occurred, advise sun avoidance and medical care if needed
• If ingestion occurred, encourage contacting Poison Control

Rutin from Safe Sources: If interested in rutin’s vascular benefits:

• Buckwheat (especially flowers and leaves) is rich source
• Citrus peel contains rutin
• Apples, berries, and other fruits contain rutin
• Supplements provide standardized rutin These provide rutin’s benefits without rue’s toxicity.

Sources

Bone, K., & Mills, S. (2013). Principles and Practice of Phytotherapy: Modern Herbal Medicine (2nd ed.). Churchill Livingstone.

Mills, S., & Bone, K. (2005). The Essential Guide to Herbal Safety. Elsevier.

Grieve, M. (1931). A Modern Herbal. Dover Publications (1971 reprint).

Pathak, M. A., Daniels, F., & Fitzpatrick, T. B. (1962). The presently known distribution of furocoumarins (psoralens) in plants. Journal of Investigative Dermatology, 39(3), 225-239.

Arora, R., Gupta, D., Chawla, R., Sagar, R., Sharma, A., Kumar, R., Prasad, J., Singh, S., Samanta, N., & Sharma, R. K. (2005). Radioprotection by plant products: Present status and future prospects. Phytotherapy Research, 19(1), 1-22.

Gonzalez, M., Zas, R., & Pernas, E. (1999). Contact photodermatitis due to rue (Ruta graveolens). Contact Dermatitis, 41(4), 232.

Ciganda, C., & Laborde, A. (2003). Herbal infusions used for induced abortion. Journal of Toxicology: Clinical Toxicology, 41(3), 235-239.

Al-Said, M. S., Tariq, M., Al-Yahya, M. A., Rafatullah, S., Ginnawi, O. T., & Ageel, A. M. (1990). Studies on Ruta chalepensis, an ancient medicinal herb still used in traditional medicine. Journal of Ethnopharmacology, 28(3), 305-312.

Opdyke, D. L. J. (1976). Monographs on fragrance raw materials: Rue oil. Food and Cosmetics Toxicology, 14(5), 463-464.

Yarnell, E. (2014). Phototoxic and photoallergic plants and herbs. Alternative and Complementary Therapies, 20(6), 332-338.

Fugh-Berman, A. (2000). Herb-drug interactions. The Lancet, 355(9198), 134-138.

Khare, C. P. (2007). Indian Medicinal Plants: An Illustrated Dictionary. Springer Science & Business Media.