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 .
A cross-over study of three oral contraceptives containing ethinyloestradiol and either desogestrel or levonorgestrel.
A r and omised cross-over trial was performed to compare the pharmacodynamic actions of three low-dose oral contraceptives ( OCs ) : Marvelon  ( 150 micrograms desogestrel (DSG)+ 30 micrograms ethinyloestradiol ( EE ) ) , Mercilon ( 150 micrograms DSG + 20 micrograms EE ) and Microgynon ( 150 micrograms levonorgestrel ( LNG ) + 30 micrograms EE ) . None of the OCs produced any significant changes in serum cholesterol , LDL-C and apoprotein B. Triglycerides were increased by the desogestrel OCs but not by Microgynon . The latter however increased the glucose and insulin responses to a glucose tolerance test whereas Marvelon and Mercilon had no effect . HDL-C increased with Marvelon , was unchanged with Mercilon and was decreased with Microgynon . Apoprotein AII was increased by all three OCs but only the DSG OCs increased apoprotein AI . All OCs produced similar increases in caeruloplasmin but the increase in SHBG was much greater with Marvelon and Mercilon than with Microgynon . Testosterone was reduced more with Microgynon than with the DSG OCs . Many of the changes reflect the strong anti-oestrogenic action of LNG on metabolic parameters compared to DSG . Except for the effect on HDL-C , there was little difference between Marvelon and Mercilon on metabolic parameters and this complements the findings from large-scale clinical trials of the two OCs . Mercilon , therefore provides a very satisfactory alternative to Marvelon
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 .