A randomized single-blind non-inferiority trial of delayed start with drospirenone-only and ethinyl estradiol-gestodene pills for ovulation inhibition.

We compared the efficacy of 4 mg drospirenone (DRSP) progestin-only pills (POPs) versus combined oral contraceptive pills (COCs) containing 0.02 mg of ethinyl estradiol (EE) and 0.075 mg of gestodene (GS) in ovulation inhibition and inducing unfavorable cervical mucus changes using a delayed-starting approach.