Effect of contraceptive steroids on serum levels of sex hormone binding globulin and caeruloplasmin

SummarySerum sex hormone binding globulin and caeruloplasmin levels were measured in women receiving 30 fig or 50 μg ethinyl oestradiol daily or a ‘triphasic’ formulation containing ethinyl oestradiol and levonorgestrel. In women taking ethinyl oestradiol alone, there was a rapid increase in the levels of both proteins, and even 10 days after the last tablet the levels were still elevated. There was no significant difference between the serum levels of the proteins in women receiving the two doses of ethinyl oestradiol, but the percentage change was significantly higher in the 50 μg group than in the 30 μg group. In women using the ‘triphasic’ formulation, levels of the proteins were significantly lower than in women taking ethinyl oestradiol alone. There was a marked variation between women in the changes produced. This marked inter-subject variation may be important in the development of side-effects in women using steroidal contraceptives.