There is no single “best time” for vinegar. Timing depends on your goal and stomach tolerance. If you have reflux or a sensitive stomach, taking it on an empty stomach may worsen burning, so using it around meals can be safer. People targeting post-meal glucose often choose near mealtimes; appetite-control users may try a diluted amount shortly before eating. Taking vinegar right before bed can worsen reflux in some people. If symptoms increase, focus on reducing dose and improving dilution—not forcing a specific time.