Levonorgestrel is a weak agonist of the androgen receptor (AR), the main biological target of the androgen sex hormone testosterone. It is a weakly androgenic progestin and in women may cause androgenic biochemical changes and side effects such as decreased sex hormone-binding globulin (SHBG) levels, decreased  cholesterol levels, weight gain, and acne.
In combination with a potent estrogen like ethinylestradiol however, all contraceptives containing androgenic progestins are negligibly androgenic in practice and in fact can be used to treat androgen-dependent conditions like acne and hirsutism in women. This is because ethinylestradiol causes a marked increase in SHBG levels and thereby decreases levels of free and hence bioactive testosterone, acting as a functional antiandrogen. Nonetheless, contraceptives containing progestins that are less androgenic increase SHBG levels to a greater extent and may be more effective for such indications. Levonorgestrel is currently the most androgenic progestin that is used in contraceptives, and contraceptives containing levonorgestrel may be less effective for androgen-dependent conditions relative to those containing other progestins that are less androgenic.