Oddly enough.. Reese's was the LAST thing we tried for pinworms... after 3 weeks of DE, albendazole, garlic and everything else that did NOT work.... after a dose of Reese's (and subsequent doses of other brand pyrantel for 3 or 4 days after that), the pinworms came out of us like the 11th commandment... and we haven't had them return. That was like, 9 or 10 weeks ago.