Adult female mice were exposed to a combination of four anabolic-androgenic steroids for 9 weeks at doses that were either one or five times the androgenic maintenance level for male mice. Relative to control females, steroid treatment depressed gonadotropin secretion and increased both dry body weight and fat content but without an increase in food intake. Steroid treatment depressed spontaneous use of a running wheel and open-field activity, and it increased aggressiveness. It also eliminated a behavior related to encounters between the sexes--the rejection of genital inspection. There was no effect of steroid treatment on the time required to recover from 10 h of enforced running on a treadmill. Overall, regardless of the test or measure, there was little or no difference in the effect of the high and low dose of steroids. This indicates a threshold of response below the low dose used in these studies, which itself is probably well below that used by many female athletes and body builders.