However , subgroup analyses for the estrogen dose and the progestin type in relation to changes in SHBG levels did show significant differences : COCs containing second generation progestins and /or the lower estrogen doses ( 20–25 µg EE ) were found to have less impact on SHBG concentrations .
The current literature review and meta- analysis demonstrates that COCs decrease circulating levels of total T and free T and increase SBHG concentrations .
Due to the SHBG increase , free T levels decrease twice as much as total T. The estrogen dose and progestin type of the COC do not influence the decline of total and free T , but both affect SHBG .
BACKGROUND Combined oral contraceptives ( COCs ) reduce levels of and rogen , especially testosterone ( T ) , by inhibiting ovarian and adrenal and rogen synthesis and by increasing levels of sex hormone-binding globulin ( SHBG ) .
Although this suppressive effect has been investigated by numerous studies over many years , to our knowledge no systematic review concerning this issue had been performed .
The effect of monophasic combinations of ethinyl estradiol and norethindrone on gonadotropins, androgens and sex hormone binding globulin: a randomized trial.
The effects of different monophasic combinations of ethinyl estradiol and norethindrone on FSH , LH , sex hormone binding globulin , total testosterone , and rostenedione , and dehydroepi and rosterone sulfate levels in non-obese , non-hirsute women were compared . Retrospective analysis of frozen serum from a prospect i ve r and omized trial in which women received one of three oral contraceptive pills containing ethinyl estradiol 50 micrograms/norethindrone 1 mg , ethinyl estradiol 35 micrograms/norethindrone 1 mg or ethinyl estradiol 35 g/norethindrone 0.5 mg for nine cycles was conducted . Blood sample s were obtained prior to treatment and during the third , sixth and ninth pill cycles . Ethinyl estradiol 50 micrograms/norethindrone 1 mg and ethinyl estradiol 35 micrograms/norethindrone 1 mg suppressed FSH , LH , and total testosterone and increased sex hormone binding globulin to a similar degree . Ethinyl estradiol 35 micrograms/norethindrone 0.5 mg result ed in less suppression of FSH , LH , and total testosterone , but greater elevation of sex hormone binding globulin . Dehydroepi and rosterone sulfate was suppressed to a similar degree with ethinyl estradiol 35 micrograms/norethindrone 1 mg and ethinyl estradiol 35 micrograms/norethindrone 0.5 mg , but ethinyl estradiol 50 micrograms/norethindrone 1 mg result ed in the least suppression of dehydroepi and rosterone sulfate .  Ethinyl estradiol 35 micrograms/norethindrone 1 mg caused greater suppression of and rostenedione than did the other two oral contraceptives . Oral contraceptive-induced changes in gonadotropins , and rogens , and sex hormone binding globulin can be predicted by considering the relative amounts of estrogen and progestin in the pill . When combined with 1 mg of norethindrone , 50 micrograms of ethinyl estradiol did not result in greater suppression of FSH , LH , or total testosterone or in greater elevation of sex hormone binding globulin than did 35 micrograms of ethinyl estradiol
However , subgroup analyses for the estrogen dose and the progestin type in relation to changes in SHBG levels did show significant differences : COCs containing second generation progestins and /or the lower estrogen doses ( 20–25 µg EE ) were found to have less impact on SHBG concentrations .
The current literature review and meta- analysis demonstrates that COCs decrease circulating levels of total T and free T and increase SBHG concentrations .
Due to the SHBG increase , free T levels decrease twice as much as total T. The estrogen dose and progestin type of the COC do not influence the decline of total and free T , but both affect SHBG .
BACKGROUND Combined oral contraceptives ( COCs ) reduce levels of and rogen , especially testosterone ( T ) , by inhibiting ovarian and adrenal and rogen synthesis and by increasing levels of sex hormone-binding globulin ( SHBG ) .
Although this suppressive effect has been investigated by numerous studies over many years , to our knowledge no systematic review concerning this issue had been performed .