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 different contraceptive treatments on the serum concentration of dehydroepiandrosterone sulfate.
Twenty-six healthy , non-hirsute women had antecubital venous blood obtained before and during treatment with various  contraceptive steroids  for the measurement of dehydroepi and rosterone sulfate ( DHEA-S ) .  Six of the women were r and omized to receive Ortho Novum 1/35 ( O/N ) , 7 were assigned to Ovcon 35 ( OV ) , and another five received Nordette ( N ) . The 6 women ingesting O/N as well as the 7 receiving OV had significant decreases in serum concentrations of DHEA-S ( p less than 0.05 ) . The percentage of decrease in DHEA-S in the O/N group ( 39 + /- 6 % ) and in the OV group ( 30 + /- 5 % ) was not statistically different . The group receiving N showed no changes from baseline measurements . Serum sample s from another 8 women who had received subcutaneous implants of levonorgestrel ( 1-Ng ) were obtained . No significant changes occurred in serum DHEA-S between baseline and six-month sample s. The data that 1-Ng alone and the combination of 1-Ng and ethinylestradiol did not change DHEA-S levels suggest that 1-Ng does not affect adrenal and rogen secretion . Because N , O/N and OV contain similar quantities of ethinylestradiol , these results indicate that norethindrone , but not 1-Ng , has a major suppressive effect upon adrenal and rogen secretion
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 .