Simaruba Drug Interactions, Uses, Safety & More

Simaruba comes from Simarouba amara, a tropical tree in the Simaroubaceae family that grows in the rainforests of Central and South America, including the Amazon region. The bark is the part most often used in traditional medicine.

For centuries, people in tropical areas have prepared the bark as a tea or other water-based extract. It has been used mainly for digestive problems such as diarrhea and dysentery, and also for fevers thought to be caused by malaria. Today it is sometimes sold as a dried bark, tincture, or capsule supplement.

It is important to know that closely related plants share similar names and uses, so product labels can be confusing. Always check exactly which species a product contains.

Simaruba is most commonly used for diarrhea, dysentery, and other digestive complaints. It has also been used traditionally for malaria and fevers and for intestinal parasites.

The evidence behind these uses is weak. Most of what we know comes from traditional use and from laboratory or animal studies, not from large, well-designed human trials. Some lab research suggests certain bark compounds can act against microbes and parasites, but this does not prove that taking the supplement helps people in real life.

Bottom line: there is not enough solid human evidence to confirm that Simaruba reliably treats any health condition. Do not use it in place of proven treatments, especially for serious illnesses like malaria.

The bark contains bitter compounds known as quassinoids (the family is famous for these very bitter substances). Lab studies have looked at these compounds for possible effects against bacteria, parasites, and the microbes that cause malaria.

Researchers think the quassinoids and related plant chemicals may interfere with the growth of certain microorganisms. However, most of this work was done in test tubes or animals, not in people, so the exact way Simaruba might work in the human body is not well understood.

There is limited high-quality safety information for Simaruba in humans. Because the bark is very bitter and contains active compounds, it should be used cautiously and ideally under the guidance of a healthcare professional.

People with stomach or digestive disorders, liver or kidney problems, or any chronic illness should check with a pharmacist or doctor first. Do not give it to infants or children without medical advice.

Pregnancy: Avoid Simaruba during pregnancy. There is not enough safety information, and some related plants are thought to affect the uterus. Breastfeeding: Safety is unknown, so it is best to avoid it while breastfeeding.

Reported side effects are not well documented, but as with many bitter herbal preparations, possible effects include nausea, vomiting, stomach upset, and loss of appetite, especially at higher amounts.

Large doses of bitter quassinoid-containing plants may cause more intense nausea and vomiting. If you notice any unusual symptoms, an allergic reaction, or signs of illness, stop using it and seek medical care.

There is no standardized, well-established dose for Simaruba. Traditional preparations were usually water-based extracts (decoctions) of the bark, but these vary widely in strength.

If you choose to use a commercial product, follow the directions on the label and do not exceed the recommended amount. Because reliable dosing guidance is lacking, it is wise to start low and check with a pharmacist or doctor first.