Traditionally used as an antiparasitic, for lice and skin parasites also for intestinal parasites and emebic infectionsAmargo Powder

Family: Simaroubaceae

Genus: Quassia

Species: amara

Synonyms: Quassia alatifolia, Q. officinalis, Q. amargo, Simaroube officinale

Price: £22.50 – 1lb / 454 gm Bag [wp_eStore_add_to_cart id=9]

Common names: amargo, bitter ash, bitterholz, bitterwood, bois amer, bois de quassia, crucete, quassia, cuassia, fliegenholz, guabo, hombre grande, jamaica bark, kashshing, maraubá, marupá, palo muneco, pau amarelo, quassia amarga, quassiawood, ruda, simaruba, simarubabaum, quassiaholz, quassia de cayenne, quassie, quina, simaba, Suriname wood

Parts Used: wood, leaves

Main Actions Other Actions Standard Dosage
  • kills parasites
  • reduces inflammation
Wood, Bark
  • kills lice
  • kills cancer cells
Infusion: 1 cup 2-3 times daily
  • expels worms
  • kills leukemia cells
Capsules: 1-2 g 2-3 times daily
  • kills insects
  • prevents tumors
Maceration: 1 cup 2-3 times daily
  • kills larva
  • kills viruses
  • treats malaria
  • dries secretions
  • prevents ulcers
  • cleanses blood
  • stimulates digestion
  • mildly laxative
  • increases bile
  • sedates
  • reduces fever
  • increases saliva

Amargo is a small tropical tree, growing only 2-6 m in height. It is indigenous to Brazil, Peru, Venezuela, Suriname, Colombia, Argentina, and Guyana. It has beautiful red flowers and fruits that turn red as they mature. Known botanically as Quassia amara, it is marketed and used interchangeably with another tree species, Picrasma excelsa. Sharing the common name of quassia (and many of Quassia amara’s constituents and uses), P. excelsa is much taller (up to 25 m in height) and occurs farther north in the tropics of Jamaica, the Caribbean, the Lesser Antilles, and northern Venezuela. In herbal medicine in the United States and Europe, very little distinction is made between the two species of trees; they are used identically and just called quassia. The name amargo means “bitter” in Spanish and describes its very bitter taste.


In the Amazon rainforest, amargo is used much in the same manner as quinine bark: for malaria and fevers and as a bitter digestive aid. It grows at lower elevations (where quinine does not) and contains many of the same antimalarial phytochemicals (plant chemicals) as quinine. In addition, it is used as an insecticide and tonic, and for hepatitis. Brazilian Indians use the leaves in a bath for measles as well as in a mouthwash used after tooth extractions. Indians in Suriname use the bark for fever and parasites. Throughout South America, amargo is a tribal remedy for debility, digestion problems, fever, liver problems, parasites, malaria, snakebite, and back spasms.

In current Brazilian herbal medicine systems, amargo is considered a tonic, digestion stimulant, blood cleanser, insecticide, and mild laxative. It is recommended for diarrhea, intestinal worms, dysentery, dyspepsia, excessive mucus, expelling worms, intestinal gas, stomachache, anemia, and liver and gastrointestinal disorders. In Peru, amargo is employed as a bitter digestive aid to stimulate gastric and other digestive secretions as well as for fevers, tuberculosis, kidney stones and gallstones. In Mexico, the wood is used for liver and gallbladder diseases and for intestinal parasites. In Nicaragua, amargo is used to expel worms and intestinal parasites as well as for malaria and anemia. Throughout South America, the bitter principles of amargo are used to stimulate the appetite and secretion of digestive juices, as well as to expel worms and intestinal parasites.

In herbal medicine in the United States and Europe, amargo is employed as a bitter tonic for stomach, gallbladder, and other digestive problems (by increasing the flow of bile, digestive juices, and saliva); as a laxative, amebicide, and insecticide; and to expel intestinal worms. In Europe, it is often found as a component in various herbal drugs that promote gallbladder, liver, and other digestive functions. In Britain, a water extract of the wood is used topically against scabies, fleas, lice, and other skin parasites. U.S. herbalist David Hoffman recommends it as an excellent remedy for dyspeptic conditions, to stimulate production of saliva and digestive juices, and to increase the appetite (as well as for lice infestations and threadworms). He also notes, “It may safely be used in all cases of lack of appetite such as anorexia nervosa and digestive sluggishness.”


Amargo bark contains many active constituents including bitter principles reported to be 50 times more bitter than quinine. While amargo contains many of the same types of antimalarial chemicals as quinine bark, it also contains another chemical called quassin. The large amount of quassin in the bark and wood gives amargo a bitterness rating of 40,000. The bark also contains the phytochemicals quassimarin and simalikalactone D. Quassimarin has demonstrated antileukemic and antitumorous properties in various studies, and simalikalactone D has been documented to have antimalarial, antiviral, antitumor, and anticancer activities. Other quassinoids have demonstrated anti-amebic actions in vivo and in vitro.

The main chemicals identified in amargo include: beta-carbolines, beta-sitostenone, beta-sitosterol, dehydroquassins, gallic acid, gentisic acid, hydroxyquassins, isoparain, isoparaines, isoquassins, malic acid, methylcanthins, methoxycanthins, methoxycantins, nigakilactone A, neo-quassins, nor-neoquassin, parain, paraines, quassialactol, quassimarin, quassins, quassinol, quassol, and simalikalactone D.


Several early clinical studies performed on amargo verified its traditional use as a natural insecticide, documenting it as an effective treatment for head lice infestation in humans. One of these studies reported a 99% effectiveness in 454 patients who had only two topical treatments one week apart. In a 1991 double-blind placebo trial on 148 children with head lice, those treated with an amargo bark extract reported fewer new cases, demonstrating a preventative activity against lice. In addition, an amargo water extract has been reported to work quite well against aphids in the garden, and researchers in India have discovered larvicidal activity against several types of insects, including mosquitoes. Since amargo has long been used for malaria in South America, researchers studied this biological effect as well. One study showed strong in vivo antimalarial activity in mice.

Amargo was reported to have antiviral activity when scientists at Texas Christian University demonstrated in 1996 that a water extract was active in vitro against cells infected with HIV. A 1978 in vivo study reported that amargo wood and/or sap extracts (as well as the isolated chemical quassimarin) inhibited the growth of leukemia in mice. Most recently, in 2002, an extract of the amargo wood was shown to have antiulcerous actions in mice, inhibiting the formation of gastric ulcers (induced by stress and various chemical means). Prior to this study, a U.S. patent was awarded on the quassinoid phytochemicals in amargo, finding them to have “remarkable antiulcer effects with low toxicities.” In another in vivo study, amargo was reported to have pain-relieving, muscle-relaxant, and sedative effects in rats and mice.


Amargo is still heavily relied upon as a natural remedy in South America for parasites of all kinds. It is slowly catching on here in North American herbal medicine practices for parasites and head lice, but it is predominately used here as a bitter digestive aid and remedy for digestive disorders. Amargo wood is on the FDA’s GRAS list (generally regarded as safe). The wood and its main bitter chemical, quassin, also are approved as food additives – and are employed in beverages and baked goods for their bitter taste. Toxicity studies performed on rats and mice reported no toxicity in oral dosages up to 5 g per kg of body weight.

Main Preparation Method: decoction or capsulesMain Actions (in order):
antiparasitic, pediculicide (kills lice), digestive stimulant, bitter digestive aid, liver bile stimulant, antilithic (prevents kidney stones) 
Main Uses:
  1. for lice and skin parasites
  2. for intestinal parasites and amebic infections
  3. for malaria
  4. for digestive problems (ulcers, dyspepsia, intestinal gas and bloating, sluggish digestion, anorexia)
  5. as a liver/gallbladder aid to increase bile and eliminate toxins and stones

Properties/Actions Documented by Research:
amebicide, analgesic (pain-reliever), anticancerous, antileukemic, antimalarial, antiparasitic, antitumorous, antiulcerous , antiviral, bitter, gastroprotective, insecticide, larvicide, muscle relaxant, pediculicide (kills lice), sedativeOther Properties/Actions Documented by Traditional Use:
antibacterial, antilithic (prevents kidney stones), antispasmodic, antivenin, carminative (expels gas), febrifuge (reduces fever), liver and gallbladder bile stimulant, digestive stimulant, hepatoprotective (liver protector), hepatotonic (tones, balances, strengthens liver functions), hypoglycemic, sialogogue (increases saliva), tonic (tones, balances, strengthens), vermifuge (expels worms)

Cautions: It interferes with fertility. Large amounts might cause nausea and stomach irritation.














Traditional Preparation: The traditional remedy as a digestive aid is 1/2 teaspoon of wood powder infused in one cup of boiling water. This is taken 10-15 minutes before or with meals. Alternatively, 1g in tablets or capsules can be taken two or three times daily on an empty stomach for an internal parasite cleanse. Another remedy calls for 2 teaspoons of wood powder or chips to be soaked in 1 cup of cold water overnight (a cold maceration). This is drunk for internal parasites, gallstones, and digestive disorders. This maceration can also be used topically for skin/hair parasites or as a bug spray, especially for aphids on plants and fleas on the dog. For head lice or fleas, prepare a cold maceration (allowing it to macerate/soak for 24 hours). Strain and pour through the hair or apply directly to the skin. It can be washed off in an hour (or simply left on the dog). For lice, repeat every three days for three applications, and for fleas, apply once monthly. Also, a small handful of amargo wood chips can be placed in backyard ponds/fountains (or a few chips in bird baths) to kill mosquito larvae without harming fish or birds.


Amargo should not be used during pregnancy.

Amargo has been documented to have an antifertility effect in studies with male rats. Men undergoing fertility treatment or those wishing to have children probably should avoid using amargo.

Large amounts of amargo can irritate the mucous membrane of the stomach and can lead to nausea and vomiting. Do not exceed recommended dosages.

Drug Interactions: None reported. However, amargo may interfere with male fertility drugs.

Brazil for anemia, anorexia, colic, debility, dental pain, diarrhea, digestion disorders, dysentery, dyspepsia, fever, flatulence, gallbladder problems, gallstones, gastrointestinal disorders, gonorrhea, kidney stones, liver problems, malaria, measles, urinary insufficiency, vaginal discharge, and as a bitter digestive stimulant
Costa Rica for diabetes, diarrhea, fever, worms
Europe for bile insufficiency, digestive disorders, fleas, gallstones, liver disease, parasites, scabies, threadworms, and as a bitter digestive stimulant
Guatemala for constipation, diabetes, high blood pressure, nervousness
Mexico for digestive disorders, gallbladder problems, intestinal parasites, liver disorders, worms, and as a digestive stimulant
Nicaragua for anemia, bug bites, intestinal parasites, malaria, stings, worms, and as an astringent
Panama for hyperglycemia, fever, liver disorders, malaria, snakebite
Peru for cleansing blood, digestive disorders, edema, fever, gallstones, hepatitis, intestinal parasites, kidney stones, stimulating digestion, tuberculosis, worms, and as an insecticide
for anorexia, cleansing blood, debility, digestive disorders, carcinoma, cirrhosis, constipation, fever, fleas, hyperglycemia, indigestion, leukemia, lice, liver disorders, malaria, parasites, scabies, snakebite, spasms, stimulating digestion, worms, and as a aphidicide and insecticide
Turkey for diarrhea, digestive difficulty, dysentery, fever, malaria, urinary insufficiency and as an astringent and tonic
United States. for alcoholism, anorexia, bowel cleansing, convalescence, debility, digestive disorders, fever, gallbladder problems, increasing saliva, intestinal parasites, lice, liver support, spasms, stimulating bile production, stimulating digestion, worms
Venezuela for constipation, dysentery, fever, worms and as a tonic
Elsewhere for amebic infections, bacterial infections, cancer, carcinoma, fever, liver disorders, malaria, snakebite, stimulating digestion, tumors, worms, and as an insecticide and tonic


The above text has been reprinted from The Healing Power of Rainforest Hearbs by Leslie Taylor. Published and copyrighted by Square One Publishers Inc., © 2005

All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, including websites, without written permission.

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† The statements contained herein have not been evaluated by the Food and Drug Administration. The information contained in this plant database file is intended for education, entertainment and information purposes only. This information is not intended to be used to diagnose, prescribe or replace proper medical care. The plant described herein is not intended to treat, cure, diagnose, mitigate or prevent any disease. Please refer to our conditions of use or using this plant database file and web site.

Referenced Quotes on Amargo

10. Quassia amara L. Simaroubaceae. “Amargo”, “Cuasia”, “Bitterwood”. Insecticidal, tonic, for fever and hepatitis (RAR). Brazilians use the leaf tea in bathing for measles (BDS), a remedy that sounds a bit better than tea of ashes of dry white dog dung. Brazilians also wash the mouth with leaf tea after tooth extraction. Surinamese “Maroons” use the bark for fever and parasites (MJP). Potent aphidicide (MJP).

24. “EFFECTS: The amaroid drug (quassinoids) stimulates secretion of gastric juices, increases appetite and aids digestion. It may also have a choleretic effect.

Homeopathic Uses: Quassia amara is used for gallbladder complaints, as bitter tonic, purgative and as anthelmintic (for ascarid and threadworms).

Dosage: Quassia Wood is used in homeopathic dilutions and in commercial pharmaceutical preparations. Daily Dosage: 500 mg.

Third-Party Published Research on Amargo

All available third-party research on amargo be found at PubMed. A partial listing of the third-party published research on amargo is shown below: Antimalarial Actions:

Mishra, K., et al. “Plasmodium falciparum: In vitro interaction of quassin and neo-quassin with artesunate, a hemisuccinate derivative of artemisinin.” Exp. Parasitol. 2009 Dec 29.

Cachet, N., et al. “Antimalarial activity of simalikalactone E, a new quassinoid from Quassia amara L. (Simaroubaceae).” Antimicrob. Agents Chemother. 2009 Oct; 53(10): 4393-8.

Houel, E., et al. “Quassinoid constituents of Quassia amara L. leaf herbal tea. Impact on its antimalarial activity and cytotoxicity.” J. Ethnopharmacol. 2009 Oct; 126(1): 114-8.

Bertani, S., et al. “Quassia amara L. (Simaroubaceae) leaf tea: Effect of the growing stage and desiccation status on the antimalarial activity of a traditional preparation.” J. Ethnopharmacol. 2007 Apr 20; 111(1):40-2.

Bertani, S., et al. “Simalikalactone D is responsible for the antimalarial properties of an amazonian traditional remedy made with Quassia amara L. (Simaroubaceae).” J. Ethnopharmacol. 2006 Nov 3;108(1):155-7.

Vigneron, M., et al. “Antimalarial remedies in French Guiana: a knowledge attitudes and practices study.” J Ethnopharmacol. 2005 Apr; 98(3): 351-60.

Bertani, S., et al. “Evaluation of French Guiana traditional antimalarial remedies.” J. Ethnopharmacol. 2005 Apr; 98(1-2): 45-54.

Ajaiyeoba, E. O., et al. “In vivo antimalarial activities of Quassia amara and Quassia undulata plant extracts in mice.” J. Ethnopharmacol. 1999; 67(3): 321–25.

O’Neill, M. J., et al. “Plants as sources of antimalarial drugs: in vitro antimalarial activities of some quassinoids.” Antimicrob. Agents Chemother. 1986; 30(1): 101–4.

Trager, W., et al. “Antimalarial activity of quassinoids against chloroquine-resistant Plasmodium falciparum in vitro.” Am. J. Trop. Med. Hyg. 1981; 30(3): 531–37.

Anti-amebic & Anti-parasitic Actions:

Ninci, M. E. “Prophylaxis and treatment of pediculosis [lice] with Quassia amarga.” Rev. Fac. Cien. Med. Univ. Nac. Cordoba 1991; 49(2): 27–31.

Wright, C. W., et al. “Use of microdilution to assess in vitro antiamoebic activities of Brucea javanica fruits, Simarouba amara stem, and a number of quassinoids.” Antimicrob. Agents Chemother. 1988; 32(11): 1725-9

Jensen, O. “Pediculosis capitis treated with Quassia tincture.” Acta. Derm. Venereol. 1978; 58(6): 557–59.

Jensen, O. “Treatment of head lice with Quassia tincture.” Ugeskr. Laeger. 1979; 141(4): 225–26.

Insecticidal & Larvicidal Actions:

Flores, G., et al. “Antifeedant activity of botanical crude extracts and their fractions on Bemisia tabaci (Homoptera: Aleyrodidae) adults: III. Quassia amara (Simaroubaceae).” Rev. Biol. Trop. 2008 Dec; 56(4): 2131-46.

Evans, D. A., et al. “Larvicidal efficacy of Quassin against Culex quinquefasciatus.” Indian J. Med. Res. 1991 Sep; 93: 324-7.

Evans, D. A., et al. “Extracts of Indian plants as mosquito larvicides.” Indian J. Med. Res. 1988; 88(1): 38–41.

Park, M. H., et al. “Acute insecticidal activity of quassin and its congeners against the American cockroach.” Chem. Pharm. Bull. 1987; 35(7): 3082-5.

Roark, R. C. “Some promising insecticidal plants.” Econ. Bot. 1947; 1: 437–45.

Anti-fertility Actions:

Parveen, S., et al. “A comprehensive evaluation of the reproductive toxicity of Quassia amara in male rats.” Reprod. Toxicol. 2003; 17(1): 45–50.

Raji, Y., et al. “Antifertility activity of Quassia amara in male rats – in vivo study.” Life Sci. 1997; 61(11): 1067-74.

Njar, V. C., et al. “Antifertility activity of Quassia amara: quassin inhibits the steroidogenesis in rat Leydig cells in vitro.” Planta Med. 1995 Apr; 61(2): 180-2.

Antimicrobial Actions:

Xu, Z., et al. “Anti-HIV agents 45(1) and antitumor agents 205. (2) Two new sesquiterpenes, leitneridanins A and B, andthe cytotoxic and anti-HIV principles from Leitneria floridana.” J. Nat. Prod. 2000; 63(12): 1712–15.

Abdel-Malek, S., et al. “Drug leads from the Kallawaya herbalists of Bolivia. 1. Background, rationale, protocol and anti-HIV activity.” J. Ethnopharmacol. 1996; 50: 157–66.

Ajaiyeoba, E.O., et al. “Antibacterial and antifungal activities of Quassia undulata and Quassia amara extracts in vitro.” Afr. J. Med. Med. Sci. 2003 Dec; 32(4): 353-6.

Apers, S., et al. “Antiviral activity of simalikalactone D, a quassinoid from Quassia africana.” Planta Med. 2002; 25(9): 1151–55.

Morre, D. J., et al. “Effect of the quassinoids glaucarubolone and simalikalactone D on growth of cells permanently infected with feline and human immunodeficiency viruses and on viral infections.” Life Sci. 1998; 62(3): 213-9.

Cytotoxic Actions:

Kupchan, S. M. “Quassimarin, a new antileukemic quassinoid from Quassia amara.” J. Org. Chem. 1976; 41(21): 3481–82.

Gastric & Anti-ulcer Actions:

Sugimoto, N., et al. “Analysis of constituents in Jamaica quassia extract, a natural bittering agent.” Shokuhin Eiseigaku Zasshi. 2003 Dec; 44(6): 328-31.

Toma, W., et al. “Antiulcerogenic activity of four extracts obtained from the bark wood of Quassia amara L. (Simaroubaceae).” Planta Med. 2002; 68(1): 20–24.

Garcia Gonzalez, M., et al. “Pharmacologic activity of the aqueous wood extract from Quassia amara (Simarubaceae) on albino rats and mice.” Rev. Biol. Trop. 1997; 44–45: 47–50.

Tada, H., et al. “Novel anti-ulcer agents and quassinoids.” U.S. patent no. 4,731,459. 1988.

Anti-inflammatory & Pain-relieving Actions:

Verma, N., et al. “Evaluation of inhibitory activities of plant extracts on production of LPS-stimulated pro-inflammatory mediators in J774 murine macrophages.” Mol. Cell Biochem. 2009 Oct 8.

Toma, W., et al. “Evaluation of the analgesic and antiedematogenic activities of Quassia amara bark extract.” J. Ethnopharmacol. 2003; 85(1): 19–23.

Chemical Constituents Identified:

Tada, A., et al. “Examination of original plant of Jamaica quassia extract, a natural bittering agent, based on composition of the constituents.” Shokuhin Eiseigaku Zasshi. 2009 Feb; 50(1): 16-21.

Ingredients: 100% pure amargo bark (Quassia amara). No binders, fillers or additives are used. This is a wild harvested plant—grown naturally in the Brazilian Amazon without any pesticides or fertilizers.

Traditional Preparation:* The traditional remedy as a digestive aid is 1/2 teaspoon of wood powder infused in one cup of boiling water. This is taken 10-15 minutes before or with meals. Alternatively, 1g in tablets or capsules can be taken two or three times daily on an empty stomach for an internal parasite cleanse. Another remedy calls for 2 teaspoons of wood powder or chips to be soaked in 1 cup of cold water overnight (a cold maceration). This is drunk for internal parasites, gallstones, and digestive disorders, and used externally for lice. For more complete instructions on preparing herbs see the Methods for Preparing Herbal Remedies Page.


Amargo should not be used during pregnancy.

Amargo has been documented to have an antifertility effect in studies with male rats. Men undergoing fertility treatment or those wishing to have children probably should avoid using amargo.

Large amounts of amargo can irritate the mucous membrane of the stomach and can lead to nausea and vomiting. Do not exceed recommended dosages.

Drug Interactions: None reported.

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