Potentially beneficial remedies

RU-21: Dietary Supplement available in most countries.
Rehydration: "Effective interventions include rehydration, prostaglandin inhibitors, and vitamin B6".
Narcotics: Codeine, dihydrocodeine, tilidine and other such medication directly work against many of the effects of alcohol hangover. However, preparations containing acetaminophen (paracetamol/Tylenol) should be avoided if possible when alcohol is in the system because of the risk of potentially fatal liver damage. Consumption of narcotics along with alcohol or shortly after consumption thereof is potentially dangerous in itself because of added depressant effects on the central nervous system.
Magnesium: It is well studied that excessive alcohol consumption can lead to a magnesium deficiency, or reduce levels of magnesium, as well as depleting zinc and other minerals. Individuals with lower magnesium levels may experience more severe hangovers. A healthy diet that contains an adequate intake of magnesium and other minerals may help in the long term to reduce the effects of hangovers. The hangover symptoms of headache, and light and sound sensitivity, are very similar to those of migraine. A common treatment for chronic migraine headaches is magnesium. Some scientists hypothesize that a hangover may be exhibiting at least some symptoms of an acute magnesium deficiency.
Opuntia ficus indica: A 2004 clinical study suggests that taking an extract of a prickly pear cactus fruit (Opuntia ficus indica) five hours before drinking had a statistically significant effect on three hangover symptoms. "Three of the 9 symptoms – nausea, dry mouth, and anorexia – were significantly reduced by OFI." (Anorexia in this context simply means loss of appetite, not to be confused with anorexia nervosa.)The authors conclude, "The symptoms of the alcohol hangover are largely due to the activation of inflammation. An extract of the OFI plant has a moderate effect on reducing hangover symptoms, apparently by inhibiting the production of inflammatory mediators."
Tolfenamic acid (TA): A study concludes, "TA was found significantly better than placebo in the subjective evaluation of drug efficacy (p<0.001) and in reducing the reported hangover symptoms in general (p < 0.01). In the TA group, significantly lower symptom scores were obtained for headache (p<0.01), and for nausea, vomiting, irritation, tremor, thirst, and dryness of mouth (all p < 0.05)."
Vitamin B6 (pyritinol): Some studies have found that Vitamin B6 reduces hangovers.
Chlormethiazole: "Chlormethiazole was found to lower blood pressure and adrenaline output and, furthermore, to relieve unpleasant physical symptoms, but did not affect fatigue and drowsiness. The cognitive test results were only slightly influenced by this agent, while psychomotor performance was significantly impaired. Subjects with severe subjective hangover seemed to benefit more from the chlormethiazole treatment than subjects with a mild hangover."However, all 8 subjects had unpleasant nasal symptoms following chlormethiazole, and it is therefore not an ideal hypnotic for this age group."
Rosiglitazone: [Study in rats] "Rosiglitazone alleviated the symptoms of ethanol-induced hangover by inducing ALD2 expression…"
Acetylcysteine: There are claims that N-acetylcysteine can relieve or prevent symptoms of hangover through scavenging of acetylaldehyde.
"Artichoke and Sarsaparilla extract": A November 2004 issued U.S. Patent No. 6,824,798 states that the method described in the patent "results in complete elimination of veisalgia (hangover) in more than 80% of individuals". These plant extracts, when administered separately, do not seem to have a similar effect. The patent further states that the right combination of the extracts of both of these plants are required and that they then contain a complex of polyphenols, flavonoids, and phytosterols that are effective.
Food and Water: Simple consumption of food and water may be enough to replenish lost moisture and at least rehydrate the body, making a hangover shorter.