Unlike many heartburn remedies Prilosec OTC effectively fights heartburn before it begins. It*s an over the counter PPI clinically proven to block heartburn for 24 hours. And that means with 1 pill a day for 14 days; you get the relief you need from the pain of frequent heartburn. While taking Prilosec OTC; heartburn won*t keep coming back. (It*s possible with Prilosec OTC. Use as directed for 14 days for treating frequent heartburn).; Blocks the burn all day and all night.; Directly blocks many of the active stomach pumps that produce acid before they start.; Works for 24 hours with one pill a day. It is indicated for a 14-day course of treatment; up to three times a year.