Oestrogens, gonadotrophins and SHBG during oral and cutaneous administration of oestradiol-17 beta to menopausal women.

Thirty-eight post-menopausal women were randomly allocated to 6 months of treatment with either 2-4 mg of micronized oestradiol-17 beta taken orally or 3 mg of oestradiol-17 beta applied cutaneously. The plasma concentrations of oestrone, oestradiol, LH, FSH and sex hormone binding globulin (SHBG) were determined twice before and after 2, 4 and 6 months of treatment. In both groups the clinical effects were satisfactory. During treatment the mean oestradiol levels showed similar increases in the two groups while the oestrone concentration was markedly raised only among those taking oestradiol orally. The mean LH and FSH concentrations were significantly lowered in both groups. SHBG was increased with both treatments although more marked in the group on oral medication. Doubling of the oral dose from 2 mg to 4 mg gave significant changes of the LH, FSH and oestrone concentrations. Thus, in the given doses, the two routes of administration seemed to have similar effects on post-menopausal symptoms and on the plasma concentrations of gonadotrophins and oestradiol. However the plasma oestrone and SHBG levels became significantly higher during the oral than during the cutaneous treatment.