What are the side effects of rue?

November 1, 2025 •

3 min read

Rue ($Ruta$ $graveolens$), a herb historically used for culinary and medicinal purposes, is now widely recognized as a potentially toxic plant with numerous serious side effects. Studies and case reports have detailed its capacity to cause significant harm, particularly when consumed in large quantities or applied incorrectly.

Quick Summary

This overview explains the significant dangers associated with using rue, including severe internal damage to the liver and kidneys, and external skin reactions exacerbated by sunlight. It details reproductive risks and necessary precautions for safe handling.

Key Points

Internal Toxicity: Consuming fresh rue or its oil can cause severe stomach pain, vomiting, and lead to serious liver and kidney damage, potentially resulting in death.
Reproductive Danger: Rue is a known abortifacient and is strictly unsafe for pregnant and breastfeeding women, as it can cause uterine contractions and miscarriage.
Phytophotodermatitis: Skin contact with fresh rue followed by sun exposure can cause painful, severe, and burn-like blistering rashes that can leave long-lasting pigmentation.
Handle with Caution: Protective gloves are necessary when handling the fresh plant to prevent severe skin reactions, especially during sunny weather.
Pre-existing Conditions: Individuals with liver or kidney problems are at higher risk and should absolutely avoid rue.
Neurological Effects: Ingesting rue can cause neurological issues like dizziness, drowsiness, sleep disturbances, and cramps.

Severe Internal Side Effects from Ingesting Rue

While some traditional practices involved consuming rue, modern medicine emphasizes its inherent toxicity and the serious risks of internal consumption. The plant contains various toxic compounds, including furoquinoline alkaloids and furocoumarins, which can cause severe reactions.

Organ Damage

Consuming large amounts of fresh rue leaves or essential oil is strongly discouraged and can be fatal. The volatile oil has an irritant quality that can lead to significant and potentially irreversible damage to vital organs.

Kidney Damage: Rue can irritate the urinary tract and is known to make existing kidney problems worse. Cases have been reported of acute renal failure following rue consumption.
Liver Damage: The plant is considered hepatotoxic, meaning it can cause liver damage. Toxic hepatitis has been reported in individuals using rue herbal medicine.

Gastrointestinal and Neurological Symptoms

Internal consumption of rue can induce a range of distressing and dangerous symptoms affecting the digestive and nervous systems.

Gastrointestinal Distress: Large doses can lead to violent stomach pain, cramps, vomiting, and diarrhea.
Neurological Issues: Reported side effects include drowsiness, dizziness, sleep disturbances, tremors, and in severe cases, convulsions or seizures.

Reproductive Risks

One of the most critical warnings regarding rue is its danger during pregnancy. The plant has long been used traditionally as an abortifacient to induce abortions, and this practice is highly dangerous.

Contractions and Miscarriage: Rue can cause uterine contractions, which may lead to a miscarriage or premature labor. Fatalities have occurred in women who have used rue to attempt an abortion.
Infertility: Some studies in animal models have indicated that rue extracts can interfere with reproductive health, including reducing sperm count.

Skin and Phototoxic Reactions

Contact with fresh rue leaves is known to cause a severe skin condition called phytophotodermatitis, which is essentially a chemical burn. This is not a true allergic reaction but a photoirritant response caused by furocoumarins like psoralens, which increase the skin's sensitivity to ultraviolet (UV) light.

Reaction Mechanism: When the plant's sap touches the skin and is then exposed to sunlight, it activates the phototoxic compounds, resulting in a burn-like reaction.
Symptoms: The reaction can manifest as intense itching, redness, inflammation, and painful blisters. These symptoms can worsen over time and leave persistent dark pigmentation on the affected areas for months.
Severity: The severity of the burn depends on the amount of contact and UV exposure. Cases have been documented ranging from minor irritation to severe, deep second-degree burns requiring extensive medical treatment.

Comparison of Internal vs. External Side Effects


Side Effect Category	Internal Ingestion (Large Dose)	External Contact (with Sunlight)
Severity	Potentially fatal	Ranges from mild rash to severe burns
Key Symptoms	Stomach pain, vomiting, diarrhea, cramps, liver/kidney damage	Redness, blistering, pain, dark pigmentation
Affected System	Digestive, neurological, renal, hepatic, reproductive	Integumentary (skin)
Cause	Toxic compounds affecting internal organs	Phototoxic furocoumarins reacting to UV light
Affected Population	Anyone ingesting large amounts, especially pregnant individuals and those with pre-existing conditions	Anyone who comes into contact with the fresh plant and gets sun exposure

Contraindications and Safe Handling

Due to its high toxicity, rue should be handled with extreme caution and is contraindicated for several populations.

Pregnant Women: Use is strictly forbidden for pregnant and breastfeeding women due to the risk of miscarriage and harm to the baby.
Individuals with Pre-existing Conditions: Those with kidney problems, liver disease, or gastrointestinal disorders should avoid rue, as it can exacerbate these conditions.
Sun Sensitivity: People on medications that increase sun sensitivity should be especially cautious, as rue can heighten this effect.
Safe Handling: When gardening or handling fresh rue, wear protective gloves and long sleeves to prevent skin contact. Wash any exposed skin thoroughly with soap and water immediately. For more information on general herbal safety, consult reliable health resources like Drugs.com.

Conclusion

In conclusion, while rue has historical associations with herbal remedies and culinary uses, its potent toxicity means it should be approached with extreme caution. The side effects of rue are diverse and potentially life-threatening, including serious internal organ damage, reproductive complications, and severe phototoxic skin burns. Given these significant risks, medicinal use is considered unsafe, and handling of the fresh plant requires protective measures. Consulting a healthcare professional is crucial before considering any form of therapeutic use to avoid dangerous adverse effects.

Frequently Asked Questions

Yes, touching the fresh leaves or sap of the rue plant can cause a chemical burn-like reaction called phytophotodermatitis, especially when followed by sun exposure, which causes blistering and rashes.

No, it is extremely dangerous and strictly contraindicated. Rue can cause uterine contractions and lead to miscarriage or abortion, with a risk of death for the mother.

Ingesting large quantities of rue is highly unsafe and can cause severe side effects, including stomach pain, cramps, vomiting, and serious damage to the kidneys and liver, potentially leading to death.

Rue contains phototoxic chemicals called furocoumarins (psoralens). When these compounds get on the skin and are exposed to UV light from the sun, they cause a severe skin reaction similar to a chemical burn.

No, rue essential oil is highly concentrated and potent. When ingested, it can cause severe organ damage, and applying it topically can lead to severe skin reactions.

The risks are lower with dried rue compared to the fresh plant, but caution is still advised. Many of the volatile and phototoxic compounds are reduced during drying, but ingesting large medicinal amounts is still considered unsafe.

If you experience a skin rash or blistering after contact with rue, wash the area thoroughly and avoid further sun exposure. For severe cases, especially with extensive blistering or pain, seek medical attention immediately.