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 .
Effects on blood lipid and androgen levels of two triphasic oral contraceptives.
At Hospital Saint-Louis in Paris France physicians compared data on 34 women using a levonorgestrel triphasic oral contraceptive ( OC ) with data on 32 women using a norgestimate triphasic OC  to examine the triphasic OCs effects on blood lipids and and rogen levels . They also compared post-OC blood lipids and and rogen levels with baseline blood lipids and and rogen levels . 47 % of all subjects smoked . After 6 cycles neither triphasic OC caused a significant difference in low density lipoprotein ( LDL ) cholesterol levels or in triglyceride levels . High density lipoprotein ( HDL ) levels in women using the norgestimate OC were significantly higher than in those using the levonorgestrel OC ( p = .001 ) . Accordingly the OCs had a significant effect on the LDL/HDL ratio . Levels of HDL subfractions ( HDL-2 and HDL-3 ) were also significantly higher in the norgestimate OC group than in the levonorgestrel OC group ( p < .01 ) . Women using the norgestimate OC had a significant increase in apolipoproteins A-1 and 1 - 2 after 6 cycles ( 12.7 % and 15.8 % respectively ; p = .001 and .0001 respectively ) . Neither triphasic OC affected a greater increase in sex hormone binding globulin ( SHBG ) levels than did the levonorgestrel OC ( 163 % vs. 72 % ; p = .0005 ) . It reduced the free testosterone level by 40 % . The levonorgestrel OC reduced it by 30 % but neither change was significant . Neither OC had an effect on body weight or blood pressure . These findings showed a trend toward lower and rogenicity with the norgestimate OC . The norgestimate OC may be beneficial since it was linked with significant increases in all HDL subfractions and SHBG
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 .