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 .
Oral contraceptives, androgens, and the sexuality of young women: II. The role of androgens
The relationships between plasma free testosterone ( FT ) and measures of sexual attitude , sexual behavior , and gender role behavior were assessed in 55 oral contraceptive-using and 53 nonusing female undergraduates .  Plasma FT and other measures of and rogenicity were substantially lower in the oral contraceptive ( OC ) group . Correlations between FT and certain behavioral and attitudinal measures were found in the OC users but not the nonusers . In the OC users , FT was positively associated with frequency of sexual intercourse but not with frequency of masturbation . It was negatively associated with restrictive sexual morality . Correlations between FT and measures of gender role behavior were negligible , and FT was unrelated to proceptivity , homosexual interest , or the use of sexual fantasy . The occurrence of some predicted correlations among pill-using women but not the nonusers requires explanation , particularly in view of the substantially lower levels of FT in the pill-using group . It is suggested that and rogen — behavior relationships in women are easily obscured by psychosocial influences and in this sample of young women such influences may have been more powerful among those not using OCs . Such psychosocial influences are likely to differ at different stages of women 's life cycles . The importance of controlling for such influences in any study of hormone — sexual behavior relationships in women is emphasized , and the need for prospect i ve studies of women before and after starting on steroidal contraception is recognized
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 .