Typical mebendazole dosing: 100 mg twice daily for 3 days for roundworm, hookworm, or whipworm; 100 mg once for pinworm (repeat in 2 weeks if needed).
Mebendazole treats a short list of intestinal worms and the exact dose depends on the parasite, the product strength available where you live, and age. This guide gathers trusted dosing ranges from regulators and clinical handbooks, then explains when a one-time chewable works and when a 3-day course fits better. You’ll also see when to repeat a dose, what side effects to watch for, and when another medicine is a better pick.
Quick Dose Table For Common Worms
Use this broad table as your starting point. Read the sections below for age limits, repeats, and product notes.
| Infection | Standard Dose | Typical Course |
|---|---|---|
| Pinworm (Enterobius) | 100 mg once | Single dose; repeat after 2 weeks if symptoms return |
| Roundworm (Ascaris) | 100 mg twice daily | 3 days |
| Hookworm (Ancylostoma, Necator) | 100 mg twice daily | 3 days |
| Whipworm (Trichuris) | 100 mg twice daily | 3 days |
Why The Dose Changes By Parasite
The drug blocks the worm’s energy use inside the gut. Pinworm clears with a single hit because the load sits near the colon and reproduces fast on skin around the anus; a repeat two weeks later mops up new hatchlings. The other three worms attach deeper in the small bowel and need steady exposure over several days to shut down growth and clear eggs being shed along the way.
How Much Mebendazole Do Adults And Kids Take — Safe Ranges
Age matters. Many labels start dosing at two years old. Some public-health programs use a chewable 500 mg tablet from one year of age. Your local pack and rules may differ. When in doubt, follow the leaflet inside your box and ask a pharmacist or doctor when the patient is near the age cut-off or weighs under 10 kg.
Adults
For roundworm, hookworm, and whipworm, the common plan is 100 mg in the morning and 100 mg in the evening for 3 days. For pinworm, one 100 mg dose clears most cases; a second dose two weeks later helps break the life cycle in households where itching and scratching spread eggs.
Children
Over two years: the same amounts as adults. Under two years: some regions avoid routine use, while others allow smaller amounts under supervision. Where under-10-kg dosing is used, a typical plan is 50 mg twice daily for 3 days for non-pinworm infections. Infants under six months are not routine candidates, and any dosing choice should come from a clinician who knows the child’s weight and risk.
Product Strengths And What You’ll See On Shelves
Two strengths are common worldwide: 100 mg chewable or tablet, and a 500 mg chewable. The 500 mg option is built for one-time mass deworming or single-dose regimens. The 100 mg strength suits the 3-day plans and the single 100 mg dose for pinworm. Suspension at 100 mg per 5 mL is also used where child-friendly liquids are stocked.
When A Repeat Dose Makes Sense
Pinworm spreads fast in families and day-care groups. A second dose two weeks after the first helps catch eggs that hatched after the initial pill. For roundworm, hookworm, and whipworm, a second 3-day cycle is rarely needed; if symptoms or stool tests say the worm is still present after about three weeks, another round can be used.
Household Hygiene Steps That Boost Cure Rates
Medicine works best when you also cut the re-exposure risk. Wash hands after toilet use and before eating. Keep nails short. Shower in the morning to reduce egg spread. Change underwear daily and hot-wash bed linens. Treat close contacts who share a bathroom when pinworm is confirmed, since the itch-scratch cycle moves eggs onto surfaces.
How To Take It And What To Avoid
Chew, Crush, Or Swallow?
Chewable tablets can be chewed and swallowed or crushed for younger children who can’t chew safely; pair with a small amount of soft food. Standard tablets are swallowed with water. Food is not needed, and fatty meals don’t add benefit for these gut-only infections.
Medicines That Clash
Do not mix mebendazole with metronidazole due to a reported skin reaction risk. Cimetidine can raise levels by slowing breakdown in the liver. If you take either, ask your doctor or pharmacist about timing or an alternate worm treatment.
Alcohol And Driving
Alcohol has no known direct interaction for these short courses. Drowsiness is uncommon. If you feel light-headed, skip driving until you’re steady.
Side Effects: What’s Common, What Needs Care
Most people feel fine. Short courses target worms in the gut and have low absorption. Mild cramps, gas, soft stools, or a transient rash can appear. Stop the drug and seek care fast if you see hives, mouth sores, blistering skin, or yellowing eyes. These are rare but serious.
Pregnancy And Breastfeeding
During pregnancy, many teams avoid use in the first trimester unless the benefit is clear. Later in pregnancy, some programs give single-dose treatment when the worm burden is high. For breastfeeding, only tiny amounts reach milk, so routine doses are widely viewed as compatible. Local guidance may differ, so ask a clinician who can weigh risks and benefits for you.
When Mebendazole Is Not The Best Choice
This drug does not treat all parasites. It is not the first pick for strongyloidiasis or tapeworm in many settings; other agents perform better. If you recently traveled, worked on farms, or have persistent diarrhea, weight loss, or anemia, stool testing can match the worm to the right medicine.
How Doses Vary Across Labels And Programs
Some countries stock only 100 mg tablets and use 3-day courses for several worms. Others carry a 500 mg chewable and favor single-dose plans for mass deworming. Both approaches appear in official documents. If your pack lists a single 500 mg chew for many mild gut worms, follow that local instruction; if your pack lists 100 mg twice daily for 3 days, use that plan instead. The core idea is steady exposure that starves the worm, either in one large chew or in six small doses spread over three days.
External Guidance You Can Trust
Regulatory and handbook sources align on the dose ranges above. You can read the FDA label for EMVERM for U.S. specifics and the BNF helminth treatment summary for UK practice.
Special Dosing Situations And Cautions
Not everyone fits the standard plan. The table below rounds up cases that need closer attention.
| Situation | Dose Advice | Extra Notes |
|---|---|---|
| Body weight <10 kg | Often avoided or halved amounts under medical supervision | Programs that permit use tend to use 50 mg twice daily for 3 days |
| Liver disease | Use with care | Drug exposure may rise; ask a prescriber to review other meds |
| Repeat pinworm in households | Single 100 mg dose for all eligible contacts | Pair with strict hygiene and a second dose at day 14 |
| Mass deworming programs | 500 mg chew once | Often given annually or twice yearly in schools |
| Metronidazole use | Avoid together | Reported severe skin reactions with the combo |
Step-By-Step Plan For A Smooth Course
Before You Start
- Confirm the likely worm based on symptoms and any stool test.
- Check the tablet strength in your pack and the leaflet dose.
- Scan your current meds for metronidazole or cimetidine.
During Treatment
- Take the pill at breakfast and dinner when on a 3-day plan.
- Chew the 500 mg tablet well; drink water after.
- Keep nails short; wash hands often; shower each morning.
After The Last Dose
- Pinworm only: plan a day-14 repeat if itching returns.
- If symptoms linger past three weeks, speak with a clinician about a second course or testing.
- If you swallowed a 500 mg single dose and feel better, no further meds are usually needed.
Frequently Asked Dosing Notes
Can I Take It With Food?
Food is not required. Swallow with water. For toddlers on suspension, a small snack can help with taste.
What If I Miss A Dose?
On a 3-day plan, take it when you remember unless it’s close to the next dose. Skip the missed dose if timing is tight; do not double up.
Do I Need A Stool Test After?
Not always. Many clinics treat based on symptoms and exposure. Testing helps when symptoms persist or when other causes are possible.
Albendazole Or Mebendazole?
Both drugs starve worms, yet they differ in absorption. Mebendazole mostly stays in the gut, which suits the four intestinal worms in this guide. Albendazole soaks in more, then converts to an active metabolite, which helps when larvae move through tissues. Many tapeworm problems use albendazole for that reason. For simple gut infections listed above, either agent may work, but labels and age limits often point to one.
Brand Names, Packs, And Availability
Two brand names show up often: Vermox and Emverm. Pharmacies may stock generics with the same strengths. Tablet shapes vary, yet dosing follows the numbers on the pack. If you have a 500 mg chewable but only need a 100 mg single dose for pinworm in a small child, avoid splitting the large chew unless your pack allows it; ask a clinician about a liquid. Supply often differs by country and season.
Bottom Line Dose Guide You Can Trust
For pinworm, one 100 mg dose, with a second in two weeks if needed. For roundworm, hookworm, and whipworm, 100 mg twice daily for 3 days. Choose the plan that matches your pack strength and local guidance, add the hygiene steps, and involve a clinician for young children, pregnancy, liver disease, or repeated treatment failures.