Deworming a human typically involves a short course of oral medication, often just a single dose repeated two weeks later. The specific treatment depends on which parasite you’re dealing with, so getting the right diagnosis is the first step. In many cases, pinworm infections (the most common intestinal worm in the U.S.) can be treated with an over-the-counter medication, while other parasites require a prescription.
Know Which Parasite You’re Treating
Different worms require different approaches, and some symptoms that feel like a parasitic infection turn out to be something else entirely. The most common intestinal parasites in humans fall into two broad categories: worms (pinworms, hookworms, roundworms, tapeworms, whipworms) and single-celled organisms like giardia. Globally, roundworm infection affects roughly 1 billion people. In the U.S., pinworms and giardia are the most frequent culprits.
Some infections cause no symptoms at all. When symptoms do appear, they typically involve digestive problems: abdominal pain, diarrhea, nausea, bloating, or unexplained weight loss. Pinworms have a distinctive calling card: intense itching around the anus, especially at night, when female worms lay eggs on the surrounding skin. Hookworms, which enter through the skin of bare feet in contaminated soil, can cause anemia and fatigue over time.
Getting a Diagnosis
If you suspect pinworms, a simple “tape test” can confirm it at home before you visit a provider. First thing in the morning, before bathing or using the toilet, press the sticky side of a piece of clear tape against the skin near the anus. Fold the tape over, seal it in a plastic bag, and bring it to your healthcare provider. Pinworm eggs will show up under a microscope. The CDC recommends doing this three mornings in a row for the most reliable result.
For other parasites, a stool sample is the standard diagnostic tool. Your provider will look for eggs, larvae, or the organisms themselves. Getting the right diagnosis matters because treatment varies significantly between parasite types.
Over-the-Counter Treatment for Pinworms
Pyrantel pamoate is available without a prescription at most pharmacies and is the go-to OTC option for pinworms. It’s a single oral dose based on body weight: 5 milligrams per pound, up to a maximum of 1 gram. For a person weighing 138 to 162 pounds, that works out to about 750 mg (three teaspoonfuls of the liquid suspension). Children under 2 years old or under 25 pounds should not take it without guidance from a physician.
One dose is not enough. The medication kills live worms but cannot destroy their eggs. You need a second dose two weeks later to catch any worms that have hatched since the first treatment. Without that second dose, reinfection is almost guaranteed.
Prescription Medications
Two other medications are commonly prescribed for intestinal worms: mebendazole and albendazole. Both are effective against a broader range of parasites than pyrantel pamoate, and the World Health Organization considers them essential medicines for deworming programs worldwide.
For pinworms, mebendazole is typically given as a single 100 mg dose, repeated in two weeks. Albendazole follows a similar pattern: one 400 mg dose, repeated two weeks later. These same drugs treat roundworms, hookworms, and whipworms, though dosing and duration change depending on the infection. Tapeworm larvae that have migrated to the brain, for example, may require 15 days or more of treatment.
The medication starts working immediately, but it can take several days to kill all the worms in your system. You may notice dead worms in your stool during this period, which is normal and expected.
Side Effects to Expect
Deworming medications are generally well tolerated, especially at the single-dose levels used for common infections. The most frequent side effects are gastrointestinal: stomach cramps, nausea, diarrhea, or gas. Some people experience headaches, dizziness, or temporary fatigue. These effects are typically mild and resolve once the medication clears your system. Serious reactions like liver problems or blood disorders are rare and more associated with prolonged treatment courses for severe infections.
Hygiene Steps During Treatment
Medication alone won’t solve the problem if you keep reinfecting yourself. Pinworm eggs can survive on surfaces for two to three weeks, so cleaning your environment during treatment is just as important as taking the pills. Here’s what to do during and immediately after treatment:
- Wash your hands with soap and water before eating, after using the toilet, and after changing diapers. Hand sanitizer is not effective against parasite eggs.
- Launder all bedding and towels in a washing machine, then dry on the highest heat setting for at least 30 minutes. If you don’t have a dryer, air dry in direct sunlight.
- Shower in the morning rather than at night. Pinworms lay eggs overnight, and a morning shower removes them before they spread.
- Keep fingernails short to reduce the chance of trapping eggs underneath them.
- Clean bathroom surfaces and frequently touched areas with soap first to remove visible contamination, then follow with an appropriate disinfectant.
- Avoid shaking out bedding or clothing, which can scatter microscopic eggs into the air.
If one person in a household has pinworms, treating the entire household at the same time is common practice, since the eggs spread so easily through shared surfaces.
What About Natural Remedies?
Papaya seeds and pumpkin seeds are the most frequently cited natural deworming remedies. A small 2007 study of 60 Nigerian children found that 71% of those given papaya seeds cleared parasites from their stool. That sounds promising, but the study was small, and no large, well-controlled trials have followed up on the results. Cleveland Clinic gastroenterologists have noted there isn’t adequate scientific evidence to declare papaya seeds effective or safe for this purpose. Papaya seeds also contain trace amounts of cyanide, making large quantities potentially harmful.
If you have a confirmed parasitic infection, proven medications are inexpensive (often under $10 for a course of treatment) and highly effective. Natural remedies are not a reliable substitute.
Preventing Reinfection Long Term
Once you’ve completed treatment, a few habits significantly reduce your chances of picking up parasites again. Wash produce thoroughly before eating it. Avoid walking barefoot in areas where soil may be contaminated with human or animal waste, particularly in tropical or subtropical regions. Drink treated or boiled water when traveling in areas with poor sanitation. Cook meat to safe internal temperatures, especially pork and freshwater fish, which can harbor tapeworm larvae.
In parts of the world where soil-transmitted worms are endemic, the WHO recommends routine preventive deworming for at-risk groups, including children and pregnant women in their second and third trimesters. These programs use the same medications, albendazole or mebendazole, distributed periodically without requiring individual diagnosis first. If you live in or have traveled to a high-risk region and have recurring symptoms, periodic screening through stool testing can catch reinfections early.