If you want to avoid a completely debilitating hangover, which type of alcohol should you absolutely avoid drinking?

Why Dark Liquor Can Make a Hangover Worse

If you’re trying to reduce the odds of a brutal hangover, dark spirits—especially bourbon—are the ones to be wary of. They contain more congeners than clear spirits such as vodka. Congeners are substances created during fermentation and distillation; some also come from aging liquor in barrels, which can add color and flavor.

Alcohol itself is still the main cause of a hangover. As your body processes it, alcohol disrupts sleep and contributes to dehydration and other effects that can leave you feeling ill. Congeners may add to the misery: research comparing drinks has found worse hangover symptoms after bourbon than after vodka, even when the amount of alcohol was similar.

What That Means in Practice

Choosing vodka instead of bourbon may lower one added source of hangover severity, but it does not make heavy drinking safe or hangover-proof. The amount you drink matters more than the color of the drink, and dark liquor can still be especially punishing when you consume a lot of it.

The practical takeaway is simple: if avoiding a severe hangover is the goal, skip dark spirits—and keep your total alcohol intake low.