For common intestinal roundworm infection (ascariasis), usual treatment is:

The CDC treatment guidance lists these regimens, and WHO also recommends single-dose albendazole 400 mg or mebendazole 500 mg for soil-transmitted worms.

Do not self-treat without medical or pharmacist advice if pregnant (especially first trimester), the patient is a child under 2 years, or there is liver disease. Seek urgent care if there is severe abdominal pain, persistent vomiting, abdominal swelling, fever, or worms coming from the mouth, as a heavy infestation can cause bowel blockage and may need different care.

For a typical adult or child aged 2 years or older:

Alternative:

Do not repeat the dose unless a clinician tells you to. For a child under 2 years, pregnancy, or severe stomach pain/vomiting, ask a doctor or pharmacist before taking it.