♪ in the dark, in the dark, in the dark ♪ ♪ in the dark ♪ ♪ the freaks come out at night, ♪ ♪ when it's dark ♪ did you know prilosec otc can stop frequent heartburn before it begins? heartburn happens when stomach acid refluxes into the esophagus. prilosec otc uses a unique delayed-release formula that helps it pass through the tough stomach acid. it then works to turn down acid production, blocking heartburn at the source. with just one pill a day, you get 24-hour heartburn protection. prilosec otc. one pill a day, 24 hours, zero heartburn.