Oral contraceptives vs injectable progestin in their effect on sexual behavior

We sought to compare sexual function and hormone concentrations in combined oral contraceptive (COC) and injectable progestin users.

Sexually active COC and depot medroxyprogesterone acetate (DMPA) users completed the Female Sexual Function Index (FSFI) questionnaire, a demographic data form, and had serum testosterone and estradiol levels measured. Multiple linear regression was used to measure associations of interest.

Among 50 subjects enrolled, COC users had lower levels of free testosterone compared to DMPA users (0.2 vs 0.6 pg/mL; P < .0001) and higher levels of estradiol (75.8 vs 62.8 pg/mL; P = .0057), but scores of desire (4.2 vs 3.8; P = .27), scores of arousal (5.0 vs 4.8; P = .46), or total scores (30.1 vs 28.8; P = .28) were no different. Demographic characteristics were similar except for ethnicity, level of education, gravidity, parity, and frequency of intercourse. In multivariate analysis, birth control type was not significantly associated with desire score or total FSFI score.

While users of COC and DMPA have significantly different sex hormone levels, they are not different in sexual function as measured by the FSFI.