Prilosec OTC® provides all-day, all-night protection against frequent heartburn. That's zero heartburn for 24 hours with just one pill a day. With Prilosec OTC®, you won't get frequent heartburn in the first place. One pill a day. 24 hours. Zero heartburn. With just one Prilosec OTC® pill a day, you can block frequent heartburn before it begins for a full 24 hours with zero heartburn. So you can get through the day - and rest at night - without the worry of heartburn flare-ups on your mind.