pH is an important biological factor in the brain as H+ alters the structure and function of many ion channels, transporters and receptors, thus affecting relevant synaptic activities and complex firing patterns. pH may change activities in the neural circuits responsible for motivation and reward, such that drug reward values or modulatory properties are modified to change drinking frequency and amount. In this study, we tested whether alcohol consumption can be affected by systemic pH in mice. C57BL/6J mice were given free access to 0.2 M NaHCO3 for 6 days, which resulted in a 0.2 pH unit increase compared to water-fed control mice ( p < 0.05; n = 6/group). Mice were then subjected to voluntary alcohol consumption in the two-bottle free choice procedure with one bottle containing water and the other containing 5-20% alcohol (5% increment for 4 days each). NaHCO3-fed mice consumed similar amounts of 5-15% alcohol as pair-fed mice but decreased the consumption of 20% alcohol (p < 0.05). Consistent with this result, NaHCO3-fed mice had decreased alcohol preference (i.e., alcohol intake/total fluid intake) at 20%. These changes were observed in both males and females. In separate experiments, mice were subjected to the two-bottle free choice procedure using water and 20% alcohol, with both bottles containing 0.05-0.4 M NaHCO3. The alcohol consumption was significantly decreased in the presence of 0.1 M or higher NaHCO3. The minimum effective dose of NaHCO3 was 0.08 g/kg body weight, calculated from the amount of alcohol mice consumed. Determined by the diarrhea scoring system, mice produced a normal state of feces after receiving 0.4 M NaHCO3 for 2 days, thus indicating negligible abdominal discomfort at this concentration. In other experiments, mice were given NaHCO3 by oral gavage and 1 hour later subjected to 20% alcohol in the drinking in the dark procedure. The alcohol consumption was significantly decreased in NaHCO3-fed mice, compared to pair-fed mice. In conclusion, our study shows that mildly raising blood pH by NaHCO3 decreases alcohol consumption in mice. Given that pH change has been considered as a consequence of alcohol metabolism, our data provide first evidence on the pH as a factor affecting alcohol consumption. This work was supported by the grant from the National Institute of Alcohol Abuse and Alcoholism (R21AA028606). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.