Oral contraceptive agents do not affect serum prolactin in normal women.

A total of 230 healthy women attending family planning clinics took part in a cross-sectional study, comparing contraceptive histories and serum prolactin levels. It was found that the distribution histogram of serum prolactin was markedly skewed to the right in all main groups, but that the distribution profile was not affected by use of oestrogen-containing contraceptives. Neither the dose of oestrogens nor duration of their use affected prolactin levels. We have thus found that currently available combined oral contraceptive agents have no effect on serum prolactin. Analysis of the skewed raw data yields a 'normal' range of 110-700 mU/l, higher than that usually accepted.