Mebendazole
Pronunciation: (meh-BEN-duh-zole).
- Generic name
- mebendazole
- Brand names
- Emverm
- Drug class
- Anthelmintic (Anti-parasitic)
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What mebendazole is and how it works
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how mebendazole works
Mebendazole works by inhibiting the worms' microtubule formation, which blocks their ability to absorb glucose and other nutrients they need to survive, leading to their death and elimination from the body. (Mechanism-of-action detail retained from the clinician-authored database record's general description, consistent with mebendazole's established anthelmintic drug class.) (2) (1)
What mebendazole is used for
Pinworm infection (Enterobius vermicularis)
Treated with a single 100 mg dose. (1)
Roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura), and hookworm (Ancylostoma duodenale, Necator americanus) infections
Treated with 100 mg twice daily (morning and evening) for 3 consecutive days. (1)
Before taking mebendazole
Do not take / not appropriate for
- known hypersensitivity to mebendazole or its excipients. (Contraindication) (1)
Tell your clinician about
(1)How to take mebendazole
- For pinworm: take 1 tablet (100 mg) as a single dose. For roundworm, whipworm, or hookworm: take 1 tablet (100 mg) in the morning and 1 tablet (100 mg) in the evening for 3 consecutive days. Tablets may be chewed, swallowed whole, or crushed and mixed with food; they can be taken with or without food, and no fasting or purging is required. If not cured 3 weeks after treatment, a second course is advised — your prescriber will decide whether retreatment is needed.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1)
Missed dose
The FDA label reviewed for this page gives no specific missed-dose protocol for mebendazole (most regimens are a single dose or a short 3-day course). If you miss a scheduled dose during a 3-day course, contact your pharmacist or prescriber for guidance rather than guessing.
Overdose
In case of overdose, seek emergency medical attention or contact a poison control center immediately. Accidental overdose may cause gastrointestinal symptoms; at higher doses, effects such as hair loss, reversible liver enzyme elevation, hepatitis, agranulocytosis, neutropenia, and kidney inflammation (glomerulonephritis) have been described. There is no specific antidote. (1)
Side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Anorexia (reduced appetite)
Incidence: Common adverse reaction
Abdominal pain
Incidence: Common adverse reaction
Diarrhea
Incidence: Common adverse reaction
Flatulence
Incidence: Common adverse reaction
Nausea and vomiting
Incidence: Common adverse reaction
Rash
Incidence: Common adverse reaction
Headache, dizziness, fever (DB-sourced, not independently confirmed as common in this pass)
Incidence: Reported in the clinician-authored database; frequency not established
Warning signs of hematologic, liver, or severe skin reaction (label-supported)
What to notice: Unusual tiredness or weakness, fever, or unexplained bruising or bleeding (possible blood-cell effects); yellowing of the skin or eyes (jaundice) or dark urine (possible liver effects); blistering or peeling rash (possible severe skin reaction)
What to do: Contact your healthcare provider promptly if any of these occur. (1)
Other concerning symptoms (DB-sourced, not independently verified in this pass)
What to notice: Severe abdominal pain; signs of allergic reaction (rash, itching, swelling, difficulty breathing)
What to do: Contact your healthcare provider promptly if any of these occur. (2)
Serious warnings
Mebendazole is contraindicated in patients with known hypersensitivity to mebendazole or its ingredients — serious
Symptoms: Mebendazole is contraindicated in patients with known hypersensitivity to mebendazole or its ingredients. Tell your prescriber about any past allergic reaction to this or similar medicines so they can determine whether mebendazole is appropriate for you.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Convulsions (seizures) have been reported in infants below the age of 1 year — mebendazole is not established as safe in children under 2 years — serious
Symptoms: Convulsions (seizures) have been reported in infants below the age of 1 year — mebendazole is not established as safe in children under 2 years.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Agranulocytosis and neutropenia (serious drops in white blood cells) have been reported with mebendazole use at higher doses and more prolonged durations than the standard regimens — serious
Symptoms: Agranulocytosis and neutropenia (serious drops in white blood cells) have been reported with mebendazole use at higher doses and more prolonged durations than the standard regimens. Contact your healthcare provider promptly for unusual tiredness, weakness, fever, or unexplained bruising or bleeding.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Stevens-Johnson syndrome/toxic epidermal necrolysis (severe, life-threatening skin reactions) have been reported when mebendazole is used together with metronidazole — serious
Symptoms: Stevens-Johnson syndrome/toxic epidermal necrolysis (severe, life-threatening skin reactions) have been reported when mebendazole is used together with metronidazole. The label states this combination should be avoided. Tell your prescriber or pharmacist about all medicines you are taking, including metronidazole.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Hepatitis and abnormal liver tests have been reported after mebendazole use — serious
Symptoms: Hepatitis and abnormal liver tests have been reported after mebendazole use. Contact your healthcare provider promptly for yellowing of the skin or eyes, dark urine, or unusual tiredness.
Action: Follow the urgency stated and seek prompt or emergency care when indicated. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Metronidazole | Concomitant use has been associated with Stevens-Johnson syndrome/toxic epidermal necrolysis (severe skin reactions). The label states this combination should be avoided. Tell your prescriber or pharmacist if you are taking metronidazole. | (1) |
| Cimetidine (DB-sourced, not independently verified in this pass) | The clinician-authored database record notes cimetidine may increase mebendazole blood levels and side-effect risk, but the reviewed FDA label does not independently confirm this specific interaction. Ask a doctor or pharmacist before combining. | (2) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Available human data have not reported a clear association between mebendazole and a risk of major birth defects or miscarriage; however, animal studies showed skeletal and soft-tissue malformations at doses as low as 10 mg/kg. Discuss the risks and benefits with your doctor if pregnant or planning pregnancy. (1)
Breastfeeding
A small amount of mebendazole is present in human milk after oral administration. No adverse effects on breastfed infants have been reported, but data are limited — tell your doctor if you are breastfeeding. (1)
Children
Approved for patients 2 years of age and older, using the same dosing as adults. Safety in children under 2 years has not been established, and convulsions have been reported in infants under 1 year. (1)
Renal_impairment
Renal: the FDA label reviewed for this page gives no specific renal-impairment dose adjustment for mebendazole. Hepatic: no specific numeric dose adjustment is given either, but impaired liver function, metabolism, or biliary elimination may lead to higher plasma concentrations — your prescriber will factor this into dosing decisions for patients with liver problems. (1)
Hepatic_impairment
Renal: the FDA label reviewed for this page gives no specific renal-impairment dose adjustment for mebendazole. Hepatic: no specific numeric dose adjustment is given either, but impaired liver function, metabolism, or biliary elimination may lead to higher plasma concentrations — your prescriber will factor this into dosing decisions for patients with liver problems. (1)
Monitoring
(1)Storage
Store at room temperature away from moisture and heat. Keep out of reach of children.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
US
Indication: Pinworm
Dose summary: 100 mg (1 tablet) as a single dose.
Renal context: The FDA label reviewed for this page gives no renal-impairment dose adjustment for mebendazole. No adjustment is specified; renal status should be assessed by the prescriber. (1)
US
Indication: Roundworm, whipworm, hookworm
Dose summary: 100 mg (1 tablet) twice daily (morning and evening) for 3 consecutive days.
Renal context: The FDA label reviewed for this page gives no renal-impairment dose adjustment for mebendazole. No adjustment is specified; renal status should be assessed by the prescriber. (1)
Hepatic guidance
The FDA label reviewed for this page gives no specific numeric hepatic-impairment dose adjustment for mebendazole, but notes that impaired liver function, metabolism, or biliary elimination may lead to higher plasma concentrations of the drug; the prescriber should factor this into dosing decisions for patients with liver problems.
Frequently asked questions
What is mebendazole used for?
Mebendazole treats gastrointestinal infections caused by pinworm, roundworm, whipworm, and hookworm in patients 2 years of age and older.
Is the dose the same for every type of worm infection?
No. Pinworm infection is treated with a single 100 mg dose, while roundworm, whipworm, and hookworm infections require 100 mg twice daily for 3 consecutive days.
Can I take mebendazole while pregnant?
Human data have not shown a clear link between mebendazole and major birth defects or miscarriage, but animal studies showed malformations at some doses. Discuss the risks and benefits with your doctor if pregnant or planning pregnancy.
Is mebendazole safe for children?
It is approved for children 2 years of age and older, using the same dosing as adults. Safety in children under 2 has not been established, and seizures have been reported in infants under 1 year.
What should I do if I miss a dose during the 3-day course?
Contact your pharmacist or prescriber for guidance rather than guessing, since a formal missed-dose protocol is not established for this short course of treatment.
Can I take mebendazole with metronidazole?
This combination should be avoided per the product label, because it has been associated with Stevens-Johnson syndrome/toxic epidermal necrolysis, a severe skin reaction. Tell your prescriber about all medicines you take, including metronidazole.
How can I prevent reinfection?
Practice good hygiene: regular handwashing, cleaning household surfaces, and frequently washing bedding and clothing. A repeat treatment course may be advised if not cured 3 weeks after the first course.
What happens if I take too much mebendazole?
Seek emergency medical attention or contact a poison control center immediately. Accidental overdose may cause gastrointestinal symptoms; higher doses have been linked to hair loss, liver enzyme changes, hepatitis, agranulocytosis, neutropenia, and kidney inflammation. There is no specific antidote.
Can I drink alcohol while taking mebendazole?
The FDA label reviewed for this page does not address alcohol use with mebendazole. Ask your doctor or pharmacist for guidance specific to your situation.
What is the mechanism of action of mebendazole?
Mebendazole works by inhibiting the worms' microtubule formation, which blocks their ability to absorb glucose and other nutrients they need to survive, leading to their death and elimination from the body. (Mechanism-of-action detail retained from the clinician-authored database record's general description, consistent with mebendazole's established anthelmintic drug class.) (2) (1)
What is the generic name of Mebendazole?
The generic name is mebendazole. It is sold under brand names including Emverm.
What class of drug is mebendazole?
Mebendazole is classed as: Anthelmintic (Anti-parasitic).
References
- EMVERM — mebendazole tablet, chewable — prescribing informationU.S. Food and Drug Administration (DailyMed) · United States · accessed 2026-08-06 · source 1
- Mebendazole — clinician-authored content (Supabase medicines table)MedGuideGlobal (clinician-authored medicine record) · null · accessed 2026-08-06 · source 2
- MEBENDAZOLE POWDER [DARMERICA, LLC] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Mebendazole — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 4
- VERMOX — FDA approval record (Drugs@FDA NDA208398)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 5
- mebendazole — RxNorm normalized drug concept (RXCUI 6672)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6
Brand names by country
Single-ingredient mebendazole names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- VERMOX500 mg · janssen pharmaceuticals, inc.
Canada
- VERMOX