Worms Medicines for Humans: Prescription and OTC options

Think you might have a worm infection? Parasitic worms can cause a range of symptoms, from intense itching around your anus at night to abdominal pain or diarrhea. You might even notice a worm in your stool.

The good news is that many worm infections can be effectively treated with medication. But the right medicine depends on the type of worm you have. Most require a prescription. But in some cases, an over-the-counter (OTC) medicine can be used.

We’ll review what you need to know about the most common options and when you may need to see a healthcare professional for testing and treatment.

What are the best deworming medicines for humans?

The best deworming medicine depends on the type of worm infection you have. Here’s a quick look at some common worm infections and the medications used to treat them.

1. Pyrantel pamoate

Pyrantel pamoate is the only OTC deworming medicine for humans available in the U.S. The rest of the options on this list are prescription medications.

Pyrantel pamoate (Reese’s Pinworm Medicine, PinX) is most commonly used to treat pinworms in adults and children ages 2 and older who weigh at least 25 lbs. It’s also sometimes prescribed off-label for hookworm or roundworm infections.

Pyrantel pamoate comes in a liquid form. It’s usually taken as a single, weight-based dose. For pinworms, a second dose 2 weeks later is usually recommended. That’s because the medicine kills worms but not their eggs.

Pyrantel pamoate is generally well tolerated. It occasionally causes stomach pain, nausea, and other temporary, gut-related side effects.

Good to know: If someone in your family catches pinworm, everyone that lives in the household should also get treated for it. This helps stop the spread of infection.

2. Mebendazole

Mebendazole (Emverm) is a prescription medication that treats several intestinal worm infections. These include: 

• Pinworms

• Roundworms

• Hookworms

• Whipworms

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Mebendazole can fight most of these infections with just a few doses. It comes as a chewable tablet for adults and kids ages 2 and older. The dose and length of treatment depend on the type of worm. Some infections require only a single dose, while others require treatment twice a day for 3 days.

The most common side effects of mebendazole include appetite changes, nausea, and diarrhea. In rare cases, it has been linked to rashes and liver problems.

Mebendazole is only available as a brand-name product. If affordability is an issue, ask your prescriber about the Emverm savings program. Eligible people may be able to pay as little as $5 for the medication.

3. Ivermectin

Ivermectin (Stromectol) is used to treat certain roundworm infections. It’s also the preferred treatment for Strongyloides — a type of parasitic worm that can invade your skin, lungs, and intestines.

Ivermectin comes as a 3 mg tablet in both brand and generic forms. It’s usually taken as a single dose. The dose depends on your body weight and the infection being treated.

Ivermectin can cause side effects such as: 

• Dizziness

• Nausea

• Diarrhea

• Itching

The medication can also interact with other medicines, so make sure your prescriber knows what you’re taking.

Good to know: Topical forms of ivermectin (Sklice, Soolantra) are also available. But these are used to treat conditions such as head lice and rosacea, not intestinal worms.

4. Albendazole

Albendazole is the only FDA-approved treatment for tapeworms. It’s also used off-label to treat many different kinds of worm infections, including: 

• Roundworms

• Hookworms

• Whipworms

• Pinworms

It works by stopping the worm from using sugar for energy, so the worm slowly dies.

Treatment can be very different depending on the infection. Some people take albendazole for only a few doses, while others need treatment for several weeks or longer.

Common side effects include nausea, stomach pain, and headache. People taking albendazole for longer periods may need blood tests or liver function tests while they're on the medication.

5. Praziquantel

Praziquantel is used to treat several types of tapeworm and fluke infections. It’s commonly used for infections such as schistosomiasis, which is caused by blood flukes.

Praziquantel is approved for adults and kids ages 1 and older. Treatment is usually short and involves giving 3 doses over the course of a single day. 

Praziquantel can cause side effects such as: 

• Dizziness

• Fatigue

• Headache

• Nausea

• Stomach discomfort

6. Triclabendazole

Triclabendazole (Egaten) is a prescription medication used to treat fascioliasis, an infection caused by liver flukes.

It’s approved for adults and children ages 6 and older. Treatment usually consists of 2 doses taken about 12 hours apart.

Possible side effects include stomach pain, sweating, and changes in appetite. Triclabendazole can also affect the heart’s electrical activity, although serious heart-related effects are uncommon.

What are signs that you might need deworming treatment?

Some worm infections cause obvious symptoms, while others cause few or no symptoms. Signs that you may have a parasitic worm infection include:

• Seeing small, white threadlike worms around the anus or in the stool

• Seeing worms or partial worm segments

• Intense anal itching, especially at night

• Abdominal pain or cramping

• Diarrhea

• Nausea or loss of appetite

• Unexplained weight loss

• Fatigue

• Cough or other respiratory symptoms, with some types of worms

A history of recent travel can also be important. Some worm infections are much more common in certain parts of the world. Exposure to contaminated soil, untreated water, or undercooked meat or fish can also increase your risk of certain infections.

But it’s important to note that these symptoms don’t necessarily mean you have worms. Fatigue, stomach cramps, and other gut symptoms are extremely common and have many possible causes. Taking a deworming medicine when you don’t have a worm infection isn't likely to help.

Can you test for worms?

Yes, testing for worms depends on the type of infection. A healthcare professional may recommend a stool, blood, or tape test to look for evidence of infection.

Pinworms don’t always require testing. Classic pinworm symptoms include intense itching around the anus at night and seeing small, white worms. If you or your child have these, a healthcare professional may be able to diagnose the infection based on symptoms alone. In other cases, testing may be needed, such as a :

• Stool test: A microscope is used to look for signs of eggs or worms in the stool. This can be used to diagnose various intestinal worms, including roundworms, hookworms, and whipworms.

• Blood test: Some worm infections, including Strongyloides, are better detected with a blood test.

• Tape test: This involves pressing clear tape to the skin around the anus first thing in the morning to collect pinworm eggs. When testing is needed, doing this for 3 mornings in a row offers the best chance of detecting the infection.

Since different worm infections require different treatments, you should discuss your symptoms with a healthcare professional before taking a deworming medicine.

How long does deworming medicine take to work?

Deworming medicine often starts working to kill the worms within days. The worms then clear out in your stool over the next few days to 2 weeks. For many intestinal worm infections, it can take up to 5 to 7 days for the symptoms, such as anal itching, to go away.

Some worms can be treated with a single dose, like roundworm and pinworm. (Pinworm just needs 1 repeat dose, 2 weeks later.) Others — especially whipworm and often hookworm and Strongyloides — are more stubborn. These usually need several days of medicine or a repeat round. Whipworm is generally the hardest to fully clear, so a healthcare professional may recheck a stool sample and retreat if needed.

What are the side effects of deworming medication?

Most treatments for worm infections are well tolerated, but they can cause side effects. Common side effects of deworming medications include: 

• Stomach pain or discomfort

• Nausea

• Diarrhea

• Headache

• Dizziness

These effects are usually mild and temporary.

The specific side effects depend on the medication and the type of worm being treated. Some medicines can cause additional side effects, particularly when used at higher doses or for longer periods.

Can you take deworming medicine to prevent worms?

In most situations in the U.S., you shouldn’t take deworming medicine “just in case” to prevent a worm infection. These medicines are used to treat worms that are already in your body. They don’t provide lasting protection against a new infection. So you can become infected if you’re exposed after you take the medicine.

There’s one important exception. In parts of the world where certain worm infections are very common, the World Health Organization (WHO) recommends regular deworming for some groups, such as schoolchildren, even without testing each person first. These public health programs may give treatment once or twice a year because people can become reinfected quickly. This is different from taking deworming medicine on your own as a preventive measure.

For most people, good hygiene, safe food and water, and avoiding exposure to contaminated soil are the best ways to prevent worm infections.

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Written by:

Karen Hovav, MD, FAAP

Karen Hovav, MD, FAAP, has more than 15 years of experience as an attending pediatrician. She has worked in a large academic center in an urban city, a small community hospital, a private practice, and an urgent care clinic.

Edited by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. A pulmonologist and hospitalist, she practiced and taught clinical medicine at hospitals in London for a decade before entering a career in health education and technology.

Reviewed by:

Christina Aungst, PharmD, MWC

Christina Aungst, PharmD, MWC is a senior pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019.

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