The paucity of randomised controlled trials is in stark contrast to the plethora of “hangover cures” marketed on the internet. This confirms the unreliability of the internet in healthcare matters.33
Our findings show that no compelling evidence exists to suggest that any conventional or complementary intervention is effective for preventing or treating alcohol hangover. Encouraging findings for their main outcome measures exist for γ linolenic acid from B officinalis
, a yeast based combination preparation, and tolfenamic acid. However, only single randomised controlled trials for each of the tested interventions were available, most were of small sample size, and all used unvalidated symptom scores. Independent replications of these studies are therefore necessary. The lack of a sensitive standard outcome measure to assess the physiological and subjective effects of alcohol hangover may be one of the reasons for the small body of evidence. The development and initial validation of the hangover symptoms scale will hopefully encourage further systematic research and will aid the integration of trial data.34
Future studies should also investigate the biological changes that occur during alcohol hangover. The trial of O ficus-indica
reported that the extract had some effects on individual symptoms, which received some media attention.27,35
The authors suggested that O ficus-indica
exerts its action by acting on prostaglandin synthesis and cytokines that are deregulated during alcohol hangover.36
This view is supported by the improvement reported for tolfenamic acid,31
a potent inhibitor of prostaglandin synthesis. However, other data also reported beneficial effects for pyritinol, a nootropic agent that seems to enhance cognitive performance, and Liv.52, an Ayurvedic herbal preparation containing eight extracts with possible effects on alcohol metabolism.18,19
These agents seem not to act directly on the prostaglandin system. Future studies should disentangle the pathology of alcohol hangover to enable the development of effective hangover interventions.
Ethical concerns may relate to research in this area. It is conceivable that positive trials might lead to considerable media interest and industry marketing, which ultimately might lead to an increase in alcohol consumption. However, little evidence exists to show that alleviation of hangover symptoms results in increased alcohol consumption.1
Conversely, no conclusive evidence shows that hangover effectively deters alcohol consumption.
Limitations of our review pertain to the potential incompleteness of the reviewed evidence. We aimed to identify all randomised controlled trials on the topic. The distorting effects on systematic reviews arising from publication bias and location bias are well documented.37-40
For this study we searched databases with a focus on the American and European literature and those that specialise in complementary medicine, and we included hand searches. We imposed no restrictions on language of publication, and the two reviewers independently appraised the clinical evidence. We are therefore confident that our search strategy located the published trials on the subject. However, whether we identified all unpublished trials has to remain uncertain.
What is already known on this topic
The alcohol hangover has substantial economic and health consequences
Compliance with moderation to prevent alcohol hangover is poor
What this study adds
Eight randomised controlled trials assessing eight different medical interventions for preventing or treating the symptoms of alcohol hangover were reviewed
No compelling evidence exists to suggest that any conventional or complementary intervention is effective for preventing or treating alcohol hangover
Our findings show that no compelling evidence exists to suggest that any complementary or conventional intervention is effective for treating or preventing the alcohol hangover. Future studies should investigate the biological changes that occur during alcohol hangover. Until the pathology of alcohol hangover is understood in more detail, an effective intervention is likely to remain elusive. The most effective way to avoid the symptoms of alcohol induced hangover is thus to practise abstinence or moderation.