The aim of this study was to characterize the normality of menstrual cycles on the basis of progesterone and estradiol levels in self-collected saliva samples. Twenty-two women, ages 19-40 years, self-collected whole unstimulated saliva specimens each morning for two consecutive menstrual cycles. On the basis of presence/timing of hormone peaks, two investigators classified 24 cycles as normal, 10 as likely normal, and 10 as clearly not normal with respect to expected profiles. Our results show that whole saliva samples collected at home on a daily basis provide a noninvasive, feasible method of determining menstrual cycle profiles.