First of all, lets discuss what causes a hangover, which I think our friends at Asap Science do quite well:
As you can see from the video, the antioxidant glutathione is crucial for removing the toxic byproducts of alcohol metabolism. So by taking a drink that contains glutathione, we should help our body get rid of acetaldehyde, right?
Well, not exactly. First of all, raising the levels of glutathione in your liver by taking glutathione orally is not very effective, our digestive tracts just don't absorb it very well. "Ok," you might say, "I actually read the website that you linked to and noticed that the drink doesn't actually contain glutathione, it contains L-carnitine, N-acetylcysteine, b-vitamins, and vitamin C which can help our liver make more glutathione!" Well, good for you for actually reading the ingredients, and maybe even doing a little Googling (and using Wikipedia), but once again, there is no evidence that taking these vitamins after 4-5 drinks will actually boost the levels of glutathione in your liver.
In other words, there was just enough science here to make it sound good, but not enough evidence for you to by this product and take it with you to your next Skeptic Convention (or wherever you like to indulge).
So what can you do to prevent a hangover? Well, you might have already clicked through to the follow up video from Asap Science, but just in case you didn't:
1) Know your limit and avoid drinking to the point of a hangover. No seriously, think about what other medical conditions you have and/or what medications you take that might make this whole situation worse.
2) Ok, so you've decided you are probably going to indulge anyway, it is your body. If you normally follow a carbohydrate controlled diet, and you know you are going to be drinking too much, now is NOT the time to stick with your diet plan, particularly if you have diabetes. First of all, you don't want a blood glucose drop making you feel miserable, second of all, alcohol inhibits the formation of glucose from your liver stores, putting you more at risk for a blood glucose drop (which could be dangerous if you take insulin to control your diabetes).
3) For the suggestion to load up on fats, have some cheese with your adult beverages, or if you don't tolerate dairy (like me) load up on nuts or guacamole.
4) Bring bottles of water with you to the party, or order a large glass/bottle of water with your first drink. I like to bring flavored sparkling water with me to parties because it's tasty and I am more likely to be able to drink more.
5) Make sure you have already have eggs in your fridge for the morning after as it will be hard to stagger to the store.
6) I prefer broth for electrolytes (homemade if you have it in your freezer) or keep organic boullion cubes around, rather than loading up on more sugary beverages like fruit juice (although a little fruit will be fine).
Take home message--know your limit, bring your own water, and skip the Mercy.