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 .
Inhibition of ovulation by an oral contraceptive containing 100 micrograms levonorgestrel in combination with 20 micrograms ethinylestradiol.
Twenty-four healthy female volunteers with normal ovulatory cycles , aged between 20 and 34 years ( 27.5 + /- 4.3 ) , were included in a single-center , non-comparative study to investigate the effect on inhibition of ovulation of an oral contraceptive containing 20 micrograms ethinylestradiol in combination with 100 micrograms levonorgestrel . At baseline , during three treatment cycles and post-treatment , ultrasonography was used to examine the ovaries , to measure follicular size , and to measure the thickness of the endometrium . Serum levels of LH , FSH , estradiol , progesterone , total testosterone , free testosterone , SHBG , and CBG were also measured . Compared with treatment cycle 1 , an increase in residual ovarian activity ( follicle grade s 4 - 5 ) was observed in cycles 2 and 3 . Mean levels of LH , FSH , 17 beta-estradiol and progesterone remained suppressed during treatment . No escape ovulation was observed during the treatment phase of the study and there were no pregnancies . Ovulation was noted to return rapidly in the posttreatment cycle . Subjective and objective tolerance of the present regimen was noted to be good . Results indicate that the monophasic oral contraceptive containing 100 micrograms levonorgestrel combined with 20 micrograms ethinylestradiol effectively inhibits ovulation , providing adequate suppression of ovarian activity
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 .