Percutaneous oestrogen therapy opposed by lynestrenol or natural progesterone--effects on circulating oestrogens, FSH, sex hormone binding globulin and pregnancy zone protein.

Three groups of post-menopausal women were treated with percutaneous 17 beta-oestradiol 3 mg daily opposed by lynestrenol 5 mg or natural micronized progesterone 200 mg and 300 mg, respectively. During 6 mth of cyclic replacement oestrogen serum levels were increased corresponding to follicular phase values. The pre-treatment ratio E1/E2 was unchanged which is in contrast to oral therapy. Progesterone had a much weaker effect on FSH levels than lynestrenol. Women treated with progestogen had regular withdrawal bleedings, while the micronized progesterone was insufficient in this respect. No increase of the oestrogen-sensitive liver proteins, sex hormone binding globulin (SHBG) and pregnancy zone protein (PZP), was recorded in spite of a marked increase in circulating oestrogens.