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 .
Clinical and hormonal effects of two contraceptives: correlation to serum concentrations of levonorgestrel and gestodene.
Two triphasic oral contraceptives containing gestodene ( GES ) ( a new progestogen ) and levonorgestrel ( LNG ) were compared with respect to contraceptive effect , cycle control , acceptability and side effects . The serum concentrations of ingested hormones were measured together with ovarian , pituitary , and some adrenal hormones , as well as sex hormone binding globulin ( SHBG ) . The contraceptive effect and cycle control were good with both preparations , and there were only a few minor side effects . SHBG was elevated 2-fold in the LNG group and 3-fold in the GES group . The  GES concentration in serum varied more than the LNG concentration , but with correction for variations in SHBG binding , less variability in actual GES and LNG concentrations was seen . Serum levels of FSH , LH , estradiol and progesterone were all depressed with both preparations . The depression was more marked in the GES group , despite lower progestogen ingestion and similar serum concentrations . Equal decreases were found in testosterone , and rostenedione and dehydroepi and rosterone sulfate ( DHEA-S ) with both preparations
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 .