The effects of oral contraceptives on SHBG and free testosterone and their relevance to premenstrual mood and sexual interest: A comparison of two triphasic formulations

(2007). The effects of oral contraceptives on SHBG and free testosterone and their relevance to premenstrual mood and sexual interest: A comparison of two triphasic formulations containing norgestimate and either 35µg or 25µg of ethinyl estradiol. Abstract: Purpose This study compared two oral contraceptives (OCs) with the same triphasic regimen of progestin (norgestimate 0.18, 0.215 and 0.25 mg) but differing doses of ethinyl estradiol (EE) — 25 and 35 μg EE — in their effects on androgens, mood and sexual interest in women starting on OCs. Methods Total testosterone (T), free testosterone (FT), sex-hormone-binding globulin (SHBG) and dehydroepiandrosterone sulphate (DHEA-S), together with measures of mood [Beck Depression Inventory (BDI)], sexual interest [Dyadic and Solitary subscales of the Sexual Desire Inventory (SDI)] and self-reported side effects were assessed before starting on the OC and again after 3 months of use. Results Sixty women, all university students, were randomized to receive either the 25 μg EE (N/EE25) or the 35 μg EE (N/EE35) pill; 12 women discontinued, leaving 48 who completed the 3-month study. Their mean age was 19.7 years (18–30) and they were predominantly white and single. Both OCs produced reductions in mean T [N/ Considerable variability in changes in mood was evident with both OCs, with some women showing predominantly negative effects (10 in N/EE35, 5 in N/EE25); others, positive effects (9 in N/EE35, 17 in N/EE25) and some, no change (four in each group). Women using N/EE25 were significantly more likely to show improvement in premenstrual mood than those in the N/EE35 group (p<.02), although there was no correlation between changes in BDI and FT or DHEA-S. Sexual interest scores did not change significantly from baseline to posttreatment with either OC (N/EE35: dyadic, from 40. Conclusion The lower EE pill reduced FT less and was associated with greater improvement in premenstrual mood. A causal relation between these two effects is uncertain.