Effects of the heptapeptide ACTH4–10 (Org OI-63) on EEG, some memory tests, and behavior were examined in 12 normal male volunteers under 30 years of age. An intravenous dose of 60 mg was compared to placebo in a Latin square design. EEG was recorded for 2 h after administration of ACTH4–10 or placebo and was quantified by power spectral density analysis. Drug differences were tested by analyses of variance and covariance. No statistical drug effect was seen on the EEG or behavioral measures. Of the psychological tests, only the digit span test showed a decrease in number of errors with ACTH4–10 (p ≤ 0.05). These results are consistent with previous studies and suggest that an intravenous bolus of ACTH4–10 has a limited effect on the brain functions tested.