The best way to prevent a bad hangover is to drink in moderation. Obviously. Or not drink at all. Barring that, you can at least minimize next-day misery by following a few science-based strategies when you imbibe.
Eat before you drink, not after you’ve already started. With no food in your stomach, the alcohol will be absorbed directly into your gut, and then quickly hit your bloodstream. Food creates a helpful buffer; the booze seeps slowly into your system instead of flooding it. Eat about an hour before you begin drinking, ideally something with protein and healthy fat.
Choose clear alcohols (gin, vodka) over dark ones. Because of how they’re produced, many dark spirits contain more impurities and organic compounds, a.k.a., congeners, and are more likely to give you stronger hangover symptoms—especially headaches—the next day.
Avoid sugary drinks—they can make you thirsty, and cause you to drink more—or caffeine—the jolt of alertness can trick you into thinking that you’re less drunk than you actually are (and cause you to drink more). And watch out for carbonated booze. Your system absorbs the alcohol more quickly because of the carbon dioxide. (This is why champagne hangovers are the worst hangovers.)
If you know that you’ve had too much to drink—ruh-roh—don’t start worrying about how bad you’re going to feel the next day. Research shows that people who catastrophize the pain of a hangover experience worse hangovers, no matter how much alcohol they’ve actually consumed.