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 .
Effect of low-dose oral contraceptive on gonadotropins, androgens, and sex hormone binding globulin in nonhirsute women.
The effectiveness of a low-dose oral contraceptive ( OC ) in suppressing plasma levels of gonadotropins , ovarian , and adrenal and rogens and stimulating sex hormone-binding globulin ( SHBG ) was evaluated prospect ively in nonhirsute women . Thirty-three women ingested 35 micrograms of ethinyl estradiol and 1 mg of norethindrone beginning within day 1 to 5 of the menstrual cycle . Baseline levels of luteinizing hormone , follicle-stimulating hormone , total testosterone ( T ) , and rostenedione ( A ) , dehydroepi and rosterone sulfate ( DHEAS ) , and SHBG were obtained before ingestion of the OC and repeated after 3 , 6 and , 9 months of OC use on day 1 to 5 of the OC " cycle " . A significant suppression of gonadotropin levels is seen in nonhirsute women .  Sex hormone binding globulin is consistently stimulated by the low-dose OC . A significant suppression of T and DHEAS is observed . No change was seen in levels of A. The demonstrated effects become evident at 3 months and are maintained at 6 and 9 months
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 .