If there is no milk involved, it is not from lactose intolerance or something like that. What is the mechanism for caffeine causing nausea?

  • My unscientific guess is the body thinks it's poisoned or something because the brain is reporting a severe overdose of adenosine due to a prior process of upregulation, see the studies here: health.stackexchange.com/a/16996/809
    – Jonathan
    Commented Jul 27, 2018 at 18:56

1 Answer 1


There are some conflicting results concerning the effect of caffeine on nausea.

One study 1 reported that caffeine withdrawal is associated with nausea and vomiting which might suggest that caffeine might reduce nausea.

However, two years ago, a study 2 was conducted in postoperative care to reduce nausea and vomiting after general anesthesia by administrating caffeine. Interestingly, patients in the caffeine group experienced more nausea than patients who received customary antiemetic prophylaxix. This would suggest a potential pro-emetic contribution of caffeine.

So, current evidence regarding the effect of caffeine on nausea is sparse (and somehow conflicting) and further studies are needed to investigate the effect of caffeine on nausea.

Edit (regarding the possible cellular mechanisms of caffeine causing nausea)

I haven't found any study investigating the effect of caffeine on nausea (ie the area postrema). The last study conducted in the postoperative care (and showed that caffeine increased postoperative nausea) did not suggest any pathway or mechanism either. So further work is needed to investigate this possible association.

  • Cool, thank you for sharing! Do you have the links to the studies you read about? Do they explain any possible mechanisms at the cellular level? Commented Sep 5, 2016 at 2:25
  • 2
    Hi! Actually when you click on the number (1 or 2), this should direct you to the two studies. Unfortunately, the last study conducted in postoperative care, could not provide a cellular mechanism on how caffeine could induce nausea and I did not find any study neither investigating this on a cellular level. I think that further studies are needed to clarify this. BW
    – S.Victor
    Commented Sep 6, 2016 at 16:48
  • Hi @S.Victor! Interesting answer. Thank you. How about adding your comment regarding the cellular mechanisms of caffeine on nausea in your answer? This would answer (or at least address) the part "what is the mechanism for caffeine causing nausea" in the original question. Thanks. Best regards. M. Arrowsmith Commented Sep 7, 2016 at 15:28
  • 1
    Indeed @M.Arrowsmith, that would make more sense! Thanks for the suggestion! BW
    – S.Victor
    Commented Sep 7, 2016 at 15:34

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