Background

Syrian rue (Peganum harmala) is a plant that is native to the western United States, Asia, Africa, and Europe. The seeds of the plant can cause hallucinations.

Syrian rue seeds contain chemicals called beta-carbolines. These chemicals cause many different effects in the body, such as stimulant effects and those that are similar to certain medicines used to treat Alzheimer disease.

People use Syrian rue for osteoarthritis, cancer, menstrual pain, and many other conditions, but there is no good scientific evidence to support these uses. It is also unsafe.

Safety Safety definitions

When taken by mouth: Syrian rue is possibly unsafe in low doses. Taking 3-4 grams of Syrian rue seeds can cause hallucinations and stimulant effects. Syrian rue is likely unsafe in higher doses. Serious side effects affecting the nervous system, heart, liver, and kidneys, as well as death, have been reported.

When applied to the skin: Syrian rue is possibly safe when diluted in olive oil.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Syrian rue is likely unsafe when taken by mouth during pregnancy or breast-feeding. Syrian rue can induce labor. It may also cause an abortion. Avoid use.

Heart conditions: Syrian rue contains the chemicals harmaline and harmine. These might cause complications in people who have a slow heart rate or heart disease.

Blockage in the stomach: Syrian rue contains the chemicals harmaline and harmine. These chemicals might cause complications in people who have a blockage in the stomach.

Liver disease: Liver damage has occurred in people who have taken Syrian rue. People with liver diseases, including hepatitis, should avoid taking Syrian rue.

Stomach ulcers: Syrian rue contains the chemicals harmaline and harmine. These chemicals might cause complications in people who have stomach ulcers.

Lung conditions: Syrian rue contains the chemicals harmaline and harmine. These chemicals might cause complications in people who have lung conditions, including asthma and chronic obstructive pulmonary disease (COPD).

Seizures: Syrian rue contains the chemicals harmaline and harmine. These chemicals might cause complications in people who have seizures.

Surgery: Syrian rue can affect levels of serotonin in the brain. This might interfere with surgical procedures. Discontinue Syrian rue use at least 2 weeks before a planned surgery.

Blockage in the urinary tract: Syrian rue contains the chemicals harmaline and harmine. These chemicals might cause complications in people who have a blockage in the urinary tract.

Effectiveness

Dosing & administration

There isn't enough reliable information to know what an appropriate dose of Syrian rue might be. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult a healthcare professional before using.

Interactions with pharmaceuticals

Caffeine

Interaction Rating=Moderate Be cautious with this combination.

Syrian rue contains a chemical called harmaline. Taking caffeine with harmaline might increase the risk for tremors.

Drying medications (Anticholinergic drugs)

Interaction Rating=Moderate Be cautious with this combination.

Syrian rue can increase a chemical in the body called acetylcholine. Acetylcholine plays a big part in many important body functions. Some medications, called anticholinergic drugs, block the effects of acetylcholine in the body. Taking Syrian rue might decrease the effects of anticholinergic drugs.

Medications changed by the liver (Cytochrome P450 2D6 (CYP2D6) substrates)

Interaction Rating=Moderate Be cautious with this combination.

Some medications are changed and broken down by the liver. Syrian rue might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates)

Interaction Rating=Moderate Be cautious with this combination.

Some medications are changed and broken down by the liver. Syrian rue might change how quickly the liver breaks down these medications. This could change the effects and side effects of these medications.

Medications that can harm the liver (Hepatotoxic drugs)

Interaction Rating=Moderate Be cautious with this combination.

Syrian rue might harm the liver. Some medications can also harm the liver. Taking Syrian rue along with a medication that can harm the liver might increase the risk of liver damage.

Medications used for Parkinson disease (Dopamine agonists)

Interaction Rating=Moderate Be cautious with this combination.

Syrian rue contains chemicals that can affect the brain. These chemicals affect the brain similarly to some medications used for Parkinson disease. Taking Syrian rue with these medications might increase their effects and side effects.

Serotonergic drugs

Interaction Rating=Moderate Be cautious with this combination.

Syrian rue might increase a brain chemical called serotonin. Some medications also have this effect. Taking Syrian rue along with these medications might increase serotonin too much. This might cause serious side effects including heart problems, seizures, and vomiting.

Various medications used for glaucoma, Alzheimer disease, and other conditions (Cholinergic drugs)

Interaction Rating=Moderate Be cautious with this combination.

Syrian rue can increase a chemical in the body called acetylcholine. Some medications that are used for glaucoma, Alzheimer disease, and other conditions, also increase acetylcholine levels. Taking Syrian rue with these medications might increase the chance of side effects.

Interactions with herbs & supplements

Ayahuasca: Syrian rue contains compounds that interfere with the breakdown of a chemical called dimethyltryptamine (DMT), which is found in ayahuasca. When levels of DMT in the body rise, serious side effects can occur. These include hallucinations, loss of consciousness, agitation, confusion, and liver damage. Do not take Syrian rue with ayahuasca.
Herbs and supplements that might harm the liver: Syrian rue might harm the liver. Taking it with other supplements that can also harm the liver might increase the risk of liver damage. Examples of supplements with this effect include garcinia, greater celandine, green tea extract, kava, and kratom.
Herbs and supplements with serotonergic properties: Syrian rue increases a brain chemical called serotonin. Taking it along with other supplements that have this effect might cause serious side effects, including heart problems, seizures, and vomiting. Examples of supplements with this effect include 5-HTP, black seed, L-tryptophan, SAMe, and St. John's wort.

Interactions with foods

Syrian rue might slow down how quickly the body breaks down a chemical called tyramine. Taking Syrian rue while eating foods that contain tyramine might increase the risk for side effects. These include aged cheese, aged or cured meats, fava beans, sauerkraut, soy sauce, or beer.