Pinworms are treated with a single dose of anti-worm medication, followed by a second dose two weeks later. One option, pyrantel pamoate, is available over the counter at most pharmacies. The treatment is straightforward, but clearing an infection for good usually requires combining medication with thorough household cleaning to break the cycle of reinfection.
Medications That Kill Pinworms
Three medications are used to treat pinworm infections. All three work by killing adult worms in the intestine, and all three require a second dose two weeks after the first.
- Pyrantel pamoate: Available without a prescription in liquid or chewable tablet form. It works by paralyzing the worms. Once paralyzed, the worms can no longer hold onto the intestinal wall and are naturally expelled from the body during bowel movements. It’s safe enough to sell over the counter because it targets receptors on the worm’s muscles that are very different from human muscle receptors.
- Mebendazole: A prescription medication taken as a single 100 mg tablet. It starves the worms by blocking their ability to absorb sugars.
- Albendazole: Also prescription-only, taken as a single 400 mg dose.
All three options are effective, but pyrantel pamoate is the most accessible starting point since you can pick it up at a drugstore without a doctor’s visit.
Why You Need a Second Dose
These medications kill live worms but cannot destroy pinworm eggs. By the time you take the first dose, a female pinworm may have already deposited thousands of eggs around the anal area, on bedding, or under fingernails. Those eggs can hatch within a few weeks, producing new worms that reinfect you.
The second dose, taken exactly two weeks later, kills any newly hatched worms before they mature enough to lay eggs of their own. Skipping this dose is the most common reason pinworm infections keep coming back. Some treatment protocols recommend a third dose at four weeks for the same reason, particularly when reinfection risk is high.
Treating the Whole Household
Pinworm eggs spread easily. They’re microscopic, survive on surfaces, and transfer through shared towels, doorknobs, and bedding. If one person in a household is infected, it’s common for others to carry the parasite without symptoms. For this reason, treating everyone in the home at the same time is the most reliable way to eliminate the infection. If only the symptomatic person is treated, someone else in the household can silently harbor pinworms and reintroduce eggs within days.
Confirming the Infection
If you’re unsure whether pinworms are actually the problem, a simple tape test can confirm it. The best time to do this is first thing in the morning, before bathing or using the toilet, because female pinworms crawl out to lay eggs during the night.
Press a strip of clear tape firmly against the skin around the anus for a few seconds, then stick the tape onto a glass slide with the sticky side down. Place it in a sealed plastic bag and bring it to your doctor, who can examine it under a microscope for eggs. Because eggs aren’t deposited every single night, the test may need to be repeated on three separate mornings to get a reliable result.
Side Effects of Treatment
Pinworm medications are generally well tolerated, especially since treatment involves just one or two single doses. Pyrantel pamoate occasionally causes stomach cramps, nausea, diarrhea, headache, or dizziness. These effects are uncommon and typically mild. Mebendazole and albendazole have similarly low side-effect profiles at the doses used for pinworms, which are much smaller than the doses used for other types of parasitic infections.
Children Under Two
Over-the-counter pyrantel pamoate labels specify that children under two years old or weighing less than 25 pounds should not take the medication without a doctor’s guidance. This doesn’t mean young children can’t be treated; it means the dosing needs to be determined by a pediatrician rather than following the package instructions. Pinworms are extremely common in young children, and doctors routinely treat them in this age group.
Pregnancy and Breastfeeding
Pinworm infections during pregnancy or while nursing can feel stressful, but the medications have been studied in these situations. Mebendazole is poorly absorbed into the bloodstream, which means very little reaches breast milk. In studies of nursing mothers taking mebendazole, the drug was either undetectable in milk or present in amounts too small to affect an infant. None of the breastfed infants in these studies experienced adverse effects. During pregnancy, the decision to treat is usually weighed against the discomfort and reinfection risk of waiting, and your doctor can help determine the best timing.
Cleaning to Prevent Reinfection
Medication handles the worms inside your body, but eggs scattered around your home can cause a new infection within weeks. A focused cleaning effort during treatment makes a real difference.
Wash all bedding, pajamas, underwear, and towels in hot water, at least 130°F, and dry them on a high heat setting. The heat kills pinworm eggs. Handle these items carefully and avoid shaking them out, which can send eggs airborne. On the morning of the first treatment dose, change and wash bedding and clothing right away to remove eggs deposited overnight.
Beyond laundry, focus on surfaces people touch frequently: toilet seats, bathroom faucets, doorknobs, and light switches. Pinworm eggs can survive on surfaces for two to three weeks under normal household conditions, so a single wipe-down isn’t enough. Continue daily cleaning of bathrooms and high-touch areas for at least two weeks after treatment.
Short fingernails help too. Eggs collect under nails when someone scratches the itchy area, then transfer to food, surfaces, or directly to the mouth. Keeping nails trimmed and washing hands thoroughly, especially before meals and after using the bathroom, cuts off one of the most common reinfection routes. Morning showers during the treatment period help wash away eggs deposited overnight before they can spread.