After an indulgent night, the principal facial foes are dehydration, puffiness, and redness. When deprived of sleep, the body releases the stress hormone cortisol, which breaks down collagen and makes skin appear dull. Meanwhile, alcohol inhibits the release of ADH, the antidiuretic hormone that maintains the body's water equilibrium, causing vital sodium, potassium, and other minerals to leak from the blood vessels and upper layers of skin into subcutaneous tissue—hence looking bloated while simultaneously lacking moisture. Engelman suggests sipping Pedialyte, the electrolyte-rich tonic intended for kids with upset stomachs. "Through osmosis, the fluids go back into the blood vessels," she says. "In an hour, your face is less puffy, and you'll feel better than if you ate a cheeseburger."
To topically alleviate dryness, L.A.-based derm Karyn Grossman, MD, advises swapping your day lotion for a rich night cream—or "if you're prone to acne," she says, "add a hyaluronic acid gel underneath your moisturizer to hydrate without piling on oils."
Alcohol also dilates blood vessels, which is why flushed cheeks might last hours after your last sip. Cold temperatures can help (Engelman suggests storing a calming face gel in the fridge), as can two other unexpected redness reducers: OTC hydrocortisone cream, which narrows blood vessels (its anti-inflammatory properties also help quash breakouts), and medicine-cabinet staple Visine. "It contains a vasoconstrictor similar to the one used in [prescription rosacea cream] Mirvaso," says Mariwalla, who suggests patting a few drops onto skin for a quick fix that lasts up to six hours. Just enough time to tide you over till the next party.