What is marupá?

Marupá is the bark of Simarouba amara, a tall tree of the American tropics. Traders have called it bitterwood for centuries. The bark is intensely bitter.

In Latin American folk medicine the bark was used for loose stools, dysentery and fever. Today it is sold as dried bark, tea, capsules or tincture.

The honest verdict: human evidence is thin. Old, small studies of one purified compound from the tree pointed to an effect on amoebic dysentery, a gut infection with blood in the stool. Long traditional use is not proof that a remedy works, and it is not proof that it is safe.

How does marupá work?

The bitterness comes from a group of plant chemicals called quassinoids. They are the reason anyone studies this bark.

In test tubes, some quassinoids slow or kill Entamoeba histolytica. That is the parasite behind amoebic dysentery. Whether a cup of bark tea does this inside your gut is not established.

Lab work also shows action against the malaria parasite and against some bacteria and fungi. These are dish tests, not people.

In animals, related bitter extracts have calmed gut cramping and loose stools. That has not been confirmed in human trials.

Bitter plants in general are thought to trigger saliva and stomach juices. This is the old reasoning behind taking bitters before a meal. It remains a traditional idea rather than a measured one.

What forms does marupá come in?

Marupá reaches buyers mainly as dried bark.

Common forms: - shredded or powdered bark, simmered as a tea - capsules of powdered bark - tinctures, which are alcohol extracts - bulk bark chips sold in Amazonian markets

Labels may read Simarouba amara, Simarouba glauca, paradise tree, dysentery bark or aceituno. Those names are not all the same plant. Check the Latin name on the pack.

The tree is also logged for pale, light timber and plywood. That wood is not the medicinal part.

Strength is not standardised anywhere. Two bags of the same product can differ a lot.

Where it comes from:

Marupá bark held a wide place in folk practice across the Amazon, the Guianas and Central America.

European records from the 1700s describe bark shipped to France for "the flux", an old word for dysentery. Later herbal texts listed it as a bitter tonic and a fever remedy. It appeared in several Western pharmacopoeias under the name simarouba bark.

Village healers in Brazil, Peru and Colombia prepared bark decoctions for gut complaints. Healers also used bark washes on skin sores.

The tree had non-medical roles too. The small purple fruit was eaten, and the seed fat went into soap and cooking oil.

By the 1800s its use was broad and well recorded. That tells you how much people relied on it, and nothing more.

What does marupá help with?

• Amoebic dysentery and other parasite gut infections: This is the use the plant is named for. Traders called it dysentery bark. Glaucarubin, one compound from the tree, was purified and given as a drug in the 1950s. Small, old reports said it cleared the parasite in many patients. Those studies were not controlled to modern standards. They tested a single purified compound, not bark tea. Standard care today is metronidazole or a similar drug. Marupá should not take their place. Untreated amoebic infection can spread to the liver.
• Diarrhoea: Traditional healers gave bark decoctions for loose stools of any cause. In animals, bitter extracts from this plant family have slowed gut movement. There are no good human trials of the bark for diarrhoea. Awkwardly, the bark can also cause nausea and gut upset itself. So the balance of help and harm is unknown.
• Fever and malaria: Marupá was one of several bitter barks used for fevers in the Amazon basin. In test tubes, quassinoids from the tree slow the malaria parasite. That is a dish result only. No human trial supports the bark as a malaria treatment. Malaria is a medical emergency and needs proper drugs fast.
• Poor appetite and weak digestion: A small bitter dose before food was a common folk habit. Bitter taste can trigger saliva and stomach juices. That general idea has some support for bitters as a group. It has not been tested for marupá specifically. No trial has measured appetite or digestion with this bark.
• Intestinal worms: Healers used the bark against worms as well as amoebae. There is some lab activity against parasites. Human evidence for worms is absent. Worm infections have cheap, proven treatments. A doctor can test a stool sample and prescribe one.

What are the side effects of marupá?

• Nausea
• Vomiting, especially at higher amounts
• Stomach pain or cramping
• Loss of appetite
• Loose stools
• Gagging from the strong bitter taste
• Skin rash or itching, rarely

Good to know:

Nausea and vomiting are the main problems, and they rise with the amount taken. Quassinoids are known to be emetic, which means they make people sick, at higher doses.

Most reports are mild and settle once the herb is stopped. Serious harm is not well documented, but neither is this bark well studied.

Repeated vomiting or diarrhoea can dry you out. That matters most in older adults and in anyone already ill.

How much marupá should you take?

• Recommended daily: This page gives label figures only. They are not advice for you. Capsule labels for powdered bark often carry about 1 to 2 grams a day, split into two or three doses. Tincture labels tend to list a few millilitres a day. Traditional teas used a small amount of bark simmered in water. None of these numbers come from trials. They come from custom and from what makers choose to print. A doctor or pharmacist should set any amount for you.
• Best time of day: Time of day has not been tested and probably does not matter much. The old habit was to take bitters shortly before a meal. That was for appetite, not for infection. If it makes you queasy, taking it earlier in the day may be easier than at bedtime.
• With or without food: Food is the gentler option for most people. The bark can cause nausea, and an empty stomach makes that more likely. Taking it with or just after food may ease that. The bitters tradition did the opposite and used it before meals. If you do that and feel sick, switch to taking it with food.
• Time to effect: Honest answer: unknown, and it may do nothing at all. Any gut effect would be expected within a few days if it happened. The bitter taste acts at once, but taste is not treatment. If you are treating a real infection and nothing improves in two days, stop and get medical care.
• How long to take it: Short use is the norm. Folk use was for days, or at most a week or two, during an illness. There is no safety data on taking it for months. Long daily use has not been studied in people. If a gut problem lasts more than two days, that is a reason to be seen, not a reason to keep dosing.