I know I was taught back in 7th grade health class the only thing that sobers a person up is time. And while I'm pretty sure that still holds true, you have a few more options when trying to shake a hangover. Just because you were a complete drunken ass last night doesn't mean you have to pay the consequences.
Sleep is the best, if not most obvious remedy. If it's the weekend, if you don't work in the morning, be smart. Sleep it off. Why be awake for a hangover?
If, like most suckers, you have a day job that wouldn't appreciate you strolling in after lunch, eyes still bloodshot and sweating vodka, the absolute next best remedy I swear by is something called Alka Seltzer Morning Relief. I don't own stock in the company, nor do I receive anything for pimping it, but I should for how much I rave about it. The box doesn't explicitly say, "for when your drunk ass had too much fun swinging from the chandeliers last night," but their website makes no qualms about it. It's a one-two punch of aspirin and caffeine that should bring you back to life in about 20 minutes. If you don't have any in your medicine cabinet yet, stop at Walgreens on your way home and stock up - you know you'll need it sooner or later. If you can't find it at the pharmacy (which is often the case) try here and have some shipped. Worth every penny. Quick note: don't confuse the Morning Relief with any of their other product lines. I don't even know what the other Alka Seltzer products do, but this one tops them all.
I'm assuming everyone's familiar with the "hair of the dog" philosophy. Turns out this practice dates back to Shakespearean times, though let's not forget they also practiced bloodletting. And Jagermeister wasn't around yet, so how serious could their hangovers have been. I've got a couple friends that swear a couple drinks in the morning are the perfect cure for what ails you, but they're both drunks and you want nothing to do with them.
If you're wise enough to plan ahead for your hangover, you've probably heard of Chaser, Hangover Stopper, and a handful of other similar products. Most of these products utilize carbon to absorb congeners while you drink and filter them out of your system, meaning you have to take them before and/or during your drunken rampage. It's been a few years since I've tried Chaser personally, but I recall only slight improvement the next day. I will say the only "pre-antidote" as we'll call this family of remedies, that I've ever been pleased with is something called Xo3. I met the inventors of Xo3 at a trade show in Las Vegas once, and aside from being really cool guys, they won me over by loading me up with tons of free samples - which were well needed on that trip. Very different in chemical makeup from the other ones - it's essentially a nutritional supplement of vitamins and other stuff generally good for you. And it's not a pill, it's a powder you make into a tasty little drink. Know what, I'll say it: if I were smart enough to plan ahead for hangovers, I would keep a box of Xo3 lying around.
I've also been told time and again that any B-complex vitamin, especially B6 and B12 are great at helping your liver metabolize alcohol, but I'm a bartender not a scientist.
I see plenty of people in my bar each night - and by plenty I mean two - that rotate water into their drinking routine after midnight. Gin & tonic, water, Gin & tonic, water, Irish Car Bomb, etc. Never had the discipline for that but I can't see how it would hurt, save for the ticket for public urination.
I've always found bacon helps, too. Still scanning the internets for supportive research, but in the mean time, I'll keep conducting my own tests.
And if nothing seems to help that throbbing eye-headache and constant nausea, enjoy the suffering. As our friends at Modern Drunkard say, "Learn to appreciate hangovers. If it was all good times every jackass would be doing it."
*On a safety note: just because your hangover may be gone doesn't mean your blood alcohol level is. And if you really rockstarred it up the night before, you may still be over the legal limit when it's time to drive to work. Two to three drinks an hour, a last call shot or two, and a nightcap while you're waiting for the pizza delivery, can easily put your BAL anywhere above a .20 (consult handy chart). Since most bodies metabolize alcohol between .01-.02 an hour, if you stop drinking at 2 am you could wake up for work at 8 am and still have at least a .08 BAL, making you over the legal limit to drive. Don't be an idiot. Don't drink and drive, especially at 8 in the morning...