AbstractAs a follow‐up to a previous study that suggested that acutely administered ethanol could decrease steady‐state brain levels of sialic acid (SA), we evaluated the time course of the ethanol effect and tested the influence of route of administration and sex.Compared to the control treatments, ethanol (2 gm/kg) significantly decreased brain SA in each of the four brain regions that were tested. The decrease was evident by 30 minutes after ethanol administration, but peak effect was reached at about 1–2 hours. The decrease occurred with either injection or self‐administration, but the greatest decrease occurred in the self‐administration group. The SA‐induced decrease was greatest in females.An ancillary part of the study included measurement of brain levels of 2‐deoxyribose (DR). Ethanol given by either route of administration caused a preferential decrease in DR levels in the cerebellum.Lesser, but statistically significant, decreases in SA and DR occurred in controls, suggesting that these chemicals are sensitive to subtle environmental contingencies associated with the experiment