Physiological variables were compared among women who had never used oral contraceptives, past users, and current users. Randomly selected subjects were aged 30 to 59 years. Blood was sampled for determination of blood glucose, serum cholesterol and triglyceride, and plasma insulin concentration. Summed postchallenge glucose and insulin values were used in analyses to represent the magnitude of response. Contours of glucose and insulin curves were represented by single numerical variables termed "G-CON" and "I-CON." Current users of oral contraceptives had significantly higher values of G-CON, I-CON, triglyceride, and systolic blood pressure than women who never used oral comtraceptives. Current users also had significantly higher levels of summed glucose, G-CON, and I-CON than former users. Use of currently prescribed oral contraceptives is associated with adverse physiological changes that are reversible after discontinuing such use.