The effect of the synthetic estradiol, 17 alpha-ethinylestradiol, and three progestogens on calcium influx was investigated in cell cultures of human aortic smooth muscle. Neither the synthetic estrogen nor the progestogens levonorgestrel, 3-keto-desogestrel, and gestodene showed, in the concentration range of 10(-9) to 10(-6) M, a significant effect on calcium influx both alone or in equimolar estrogen-gestagen combinations. The results indicate that these substances, commonly used in contraceptive pills, do not change vasotonus interfering with calcium homeostasis.