Abstract

The levels of four serum proteins, assayed by a radial immunodiffusion technique, have been measured in healthy women who had been given either the oestrogen or progestogen component of a combined oral contraceptive preparation for three weeks. Raised α₂-macroglobulin and transferrin levels were found after oestrogen treatment but albumin and IgG did not significantly alter. In the progestogen-treated group all four proteins remained unchanged. The four proteins have also been assayed at frequent intervals during the normal menstrual cycle. No evidence of cyclical variation was found.