Also indexed as: Giardia, Pinworms, Worms
Food and water: sources of life—but also possible sources
of parasites. Rid yourself of these intestinal pests and the infections they cause. According
to research or other evidence, the following self-care steps may be helpful:
- Stay hydrated
- When diarrhea strikes, replace lost fluids and replenish
electrolytes by drinking sports drinks or other rehydration solutions
- Make prevention a priority
- When traveling to areas where parasitic infections are common,
don’t drink the tap water and avoid uncooked foods, foods prepared by street vendors,
ice, and fruits that cannot be peeled
- Soothe the symptoms
- Stop diarrhea and reduce upset stomach with over-the-counter
remedies, such as loperamide (Imodium A-D) and bismuth subsalicylate (Pepto-Bismol)
- Try a natural treatment
- Talk to a professional about treating parasitic infections with
natural antimicrobials, such as propolis, and berberine-containing herbs, including barberry,
Oregon grape, goldenseal, and goldthread (Coptis chinensis)
- Talk to your doctor
- Ask about medications used to kill intestinal parasites, such as
mebendazole (Vermox), thiabendazole (Mintezol), and metronidazole (Flagyl), and medications
used to alleviate diarrhea, such as loperamide (Imodium) and diphenoxylate (Lomotil)
These recommendations are not comprehensive and are not intended to replace
the advice of your doctor or pharmacist. Continue reading the full parasites article for more
in-depth, fully-referenced information on medicines, vitamins, herbs, and dietary and
lifestyle changes that may be helpful.
Parasites are organisms larger than yeast or bacteria that can cause infection, usually in the intestines. The most common
parasites to infect humans in the United States and Canada are giardia (Giardia
lamblia), Entamoeba histolytica, cryptosporidium (Cryptosporidium
spp.), roundworm (Ascaris lumbricoides), hookworm (Ancylostoma duodenale and
Necator americanus), pinworm (Enterobius vermicularis), and tapeworm
Infection with parasites can be life-threatening in people with severe impairment of immune function. People should consult a
physician if they suspect a parasitic infection.
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What are the symptoms?
Parasite infections can lead to a variety of symptoms, including gas, bloating, diarrhea, weight loss, abdominal cramping and pain, constipation, nausea, vomiting, loss of appetite,
fever, rash, cough, itching anus, and bloody
or foul-smelling stools.
Dietary changes that may be helpful
When traveling in developing countries, people should avoid drinking tap water and eating
uncooked foods, foods prepared by street vendors, ice, and fruits that cannot be peeled. All
of these are potential sources of parasitic infection. People should not drink untreated
stream water while camping, as it is frequently almost invariably contaminated with giardia,
even in the United States. Undercooked fish, meat and poultry can also contain parasites.
Severe diarrhea may require hospitalization
for urgent fluid and electrolyte replacement, especially in children and the elderly.
Vitamins that may be helpful
Propolis is a resinous substance collected
by bees from the leaf buds and bark of trees, especially poplar and conifer trees. The
antimicrobial properties of propolis may help protect against parasitic infections in the gastrointestinal tract. One
preliminary trial of propolis extract for children and adults with giardiasis showed a 52%
rate of successful parasite elimination in children and a 60% elimination rate in adults
(amount not stated).1 These results are not as impressive as those achieved with
conventional drugs for giardiasis, though, so propolis should not be used as the sole therapy
for parasites without first consulting a physician about available medical treatment.
Are there any side effects or interactions?
Refer to the individual supplement for information about any side effects or interactions.
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Herbs that may be helpful
Berberine is derived from several plants, including barberry,
Oregon grape, goldenseal, and goldthread
(Coptis chinensis). Preliminary trials have shown that berberine can be used
successfully to treat giardia
infections.2 3 In addition, test tube studies show that berberine
kills amoebae, although it is not known whether this effect occurs in humans.4 The
amount required is approximately 200 mg three times per day for an adult—a level high
enough to potentially cause side effects. Therefore, berberine should not be used without
consulting a healthcare provider.
Seeds of the papaya fruit, Carica papaya, have been used in folk medicine to treat
intestinal parasites. In a preliminary trial conducted in Nigeria, treatment with papaya seeds
eradicated intestinal parasites in 71 to 100% of children, depending on the parasite being
treated. Parasites that were successfully eradicated were A. lumbricoides, E. histolytica,
N. americanus, S. stercoralis, T. trichiura, G. lamblia, and T. saginata.
Treatment consisted of a single administration of 20 ml of an elixir containing 4 grams of
air-dried and blended papaya seeds.5
Emetine and other alkaloids in ipecac kill
several types of parasites, including amoeba, pinworms, and tapeworms.6
7 Generally the amounts of ipecac needed to produce these effects in people are high and
can lead to severe side effects. Emetine or its somewhat safer form, dihydroemetine, are
reserved for rare cases of people infected with amoebae who are not cured by using anti-amoeba
drugs.8 Because of the danger involved, ipecac and emetine should never be used
without first consulting a physician.
In a preliminary trial, patients with schistosomiasis (a parasitic infection) were treated
with a combination of resin and volatile oil of
myrrh, in the amount of 10 mg per 2.2 pounds of body weight per day for three days. The
cure rate was 91.7% and, of those who did not respond, 76.5% were cured by a second six-day
course of treatment, increasing the overall cure rate to 98.1%.9
Garlic has been demonstrated to kill
parasites, including amoeba10 and hookworm,11 in test tubes and in
animals. Older studies in humans support the use of garlic to treat roundworm, pinworm, and
hookworm.12 However, due to a lack of clinical trials, the amount of garlic needed
to treat intestinal parasites in humans is not known.
Wormseed (Chenopodium ambrosioides) is a traditional remedy for infections with
worms. However, a study in Mexico found that the powdered herb was not effective at
eradicating hookworm, roundworm, or whipworm.13
Pumpkin seeds (Cucurbita
pepo) have purported effects against tapeworms. Given their safety, they are often
recommended as an addition to other, more reliable therapies. In Germany, 200–400 grams
are commonly ground and taken with milk and honey, followed by castor oil two hours
later.14 Tapeworms can cause severe illness and should be treated only with medical
supervision. In China, pumpkin seeds have been shown to effectively treat acute
schistosomiasis, a severe parasitic disease occurring primarily in Asia and Africa that is
transmitted by snails.15 The assistance of a physician is required to help diagnose
and treat any suspected intestinal parasite infection.
Several other herbs are traditionally used for treatment of parasites, including male fern
(Dryopteris filix mas) root, tansy (Tanacetum vulgare) leaf, wormwood,
sweet Annie, black walnut (Juglans nigra) fruit, and cloves (Syzygium
aromaticum). Numerous case reports and preliminary studies from the late 1800s and early
1900s have suggested some of these herbs can be helpful for some parasitic
In some cultures, it was customary to bathe in
chaparral once per year to eliminate skin parasites and to detoxify; however, there is no
modern research demonstrating the effectiveness of this use of chaparral.
Anise may have modest antiparasitic actions
and has been recommended by some practitioners as a treatment for mild intestinal parasite
Curled mint (Mentha crispa) leaf, a close relative of peppermint, has been shown in a preliminary trial to
help relieve the symptoms of giardia and amoeba infections in children and adults, as well as
to eliminate these parasites in many cases.18 This study used a tincture of curled
mint in the amount of 2 ml three times per day for five days, or 1 ml three times per day for
five days for children. Given their close relationship, peppermint could probably be
substituted for curled mint when curled mint is unavailable.
Caution: Any herb potent enough to kill parasites could potentially
harm the person taking it. Although some of these herbs have antiparasitic actions in test
tubes,19 none has been adequately tested in modern trials for efficacy or safety in
humans. Safe and proper use requires the skills of an experienced practitioner.
Are there any side effects or interactions?
Refer to the individual herb for information about any side effects or interactions.
1. Miyares C, Hollands I, Castaneda C, et al. Clinical trial with a
preparation based on propolis “propolisina” in human giardiasis. Acta
Gastroenterol Latinoam 1988;18:195–201.
2. Gupte S. Use of berberine in treatment of giardiasis. Am J Dis
3. Choudhry VP, Sabir M, Bhide VN. Berberine in giardiasis. Indian
4. Kaneda Y, Torii M, Tanaka T, Aikawa M. In vitro effects of berberine
sulphate on the growth and structure of Entamoeba histolytica, Giardia lamblia and Trichomonas
vaginalis. Ann Trop Med Parasitol 1991;85:417–25.
5. Okeniyi JAO, Ogunlesi TA, Oyelami OA, Adeyemi LA. Effectiveness of
dried Carica papaya seeds against human intestinal parasitosis: a pilot study. J Med
6. Oelkers HA. Studies on anthelmintics. Arzneimittelforschung
7. Wright CW, Phillipson JD. Natural products and the development of
selective antiprotozoal drugs. Phytother Res 1990;4:127–39 [review].
8. Schmeller T, Wink M. Utilization of alkaloids in modern medicine. In:
Roberts M, Wink M, eds. Alkaloids—Biochemistry, Ecology and Medicinal
Applications. New York: Plenum Press, 1998, 435–59 [review].
9. Sheir Z, Nasr AA, Massoud A, et al. A safe, effective, herbal
antischistosomal therapy derived from myrrh. Am J Trop Med Hyg
10. Mirelman D, Monheit D, Varon S. Inhibition of growth of Entamoeba
histolytica by allicin, the active principle of garlic extract (Allium sativum). J Infect
11. Bastidas CJ. Effect of ingested garlic on Necator americanus and
Ancylostoma caninum. Am J Trop Med Hyg 1969;13:920–3.
12. Koch HP, Lawson LD, eds. Garlic: The Science and Therapeutic
Application of Allium sativum L. and Related Species. Baltimore: Williams & Wilkins,
13. Kliks MM. Studies on the traditional herbal anthelmintic Chenopodium
ambrosioides L.: Ethnopharmacological evaluation and clinical field trials. Soc Sci
14. Weiss RF. Herbal Medicine. Beaconsfield, UK: Beaconsfield
Publishers Ltd., 1985, 119–20.
15. Chou HC, Ming H. Pumpkin seed (Cucurbita moschata) in the
treatment of acute schistosomiasis. Chin Med J 1960;80:115–20.
16. Chopra RN, Chandler AC. Anthelmintics and Their Uses in Medical
and Veterinary Practice. Baltimore: Williams & Wilkins Co, 1928.
17. Weiss RF. Herbal Medicine. Gothenberg, Sweden: Ab Arcanum
and Beaconsfield: Beaconsfield Publishers Ltd., 1985, 203–4.
18. de Santana CF, de Almeida ER, Dos Santos ER, Souza IA. Action of
Mentha crispa hydroethanolic extract in patients bearing intestinal protozoan.
19. Mendiola J, Bosa M, Perez N, et al. Extracts of Artemisia abrotanum
and Artemisia absinthium inhibit growth of Naegleria fowleri in vitro. Trans R Soc Trop
Med Hyg 1991;85:78–9.
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