The Congener Theory
Congeners are chemical byproducts of alcohol fermentation and aging — they include compounds like methanol, acetone, tannins, histamines and other chemicals. They contribute to the flavor and character of different alcoholic drinks, and they're also associated with worse hangovers.
Red wine has significantly more congeners than white wine. This is partly why red wine hangovers have a reputation for being particularly bad.
Tannins and Histamines
Red wine contains tannins (polyphenolic compounds from grape skins) and histamines. Histamines are associated with headaches, flushing and nasal congestion in some people. This "red wine headache" phenomenon is real and distinct from a standard hangover — it can occur after even small amounts of red wine in susceptible individuals.
What the Evidence Says
Studies on congener content and hangover severity generally support the idea that darker liquors (bourbon, whisky, brandy) produce worse hangovers than lighter ones (vodka, gin, white wine) at equivalent alcohol doses. Red wine sits in an intermediate position — worse than white wine on average due to congener content, but not as bad as the darkest spirits.
What to Do About It
The congener issue doesn't change the core hangover mechanism — acetaldehyde is still the primary driver regardless of what you drank. The before-bed routine (water + Revive) addresses acetaldehyde, B vitamin depletion and sleep quality irrespective of drink type. Some people sensitive to tannins also benefit from antihistamines before red wine drinking specifically.