Mechanism of action of norgestrel 0.075 mg a progestogen-only pill. I. Effect on ovarian activity

Opill

“…The 0.075-mg dosage was found to inhibit ovulation in two-thirds of women in one study. 4 Additionally, this dosage caused cervical mucus changes unfavorable to fertility in all participants. 5 The combination of these two effects provides contraceptive efficacy with consistent use.…”

The effect of deliberate non-adherence to a norgestrel progestin-only pill: A randomized, crossover study

“…We compared outcomes from the two cycles of deliberate misuse of norgestrel 0.075 mg with data from the baseline cycle of correct use, [6,7] and include data from this cycle in Appendix C. During correct use, 12 participants (24%) ovulated with a normal luteal phase. Similar proportions of normal ovulatory cycles occurred despite a delayed (22%) or missed pill (26%) (Appendix C).…”

“…We assessed the theoretical conception risk based on the presence of potentially fertile mucus in the fertile window of an ovulatory cycle. We have previously reported the results from a baseline cycle of correct daily use for cervical mucus characteristics [6] and ovarian activity status [7], included baseline demographics of the study population. Here we report the effects of a delayed or missed pill.…”

Norgestrel for nonprescription contraception: What you and your patients need to know

“…During this cycle, most participants (n = 34/51; 67%) did not ovulate, confirming that norgestrel 0.075 mg does impact ovulation. 6 Most participants also had unfavorable cervical mucus (n = 39/51; 76%). 6 Overall, 94% had full protection against pregnancy, either through lack of ovulation (n = 9), unfavorable mucus (n = 14), or both (n = 25).…”

“…6 Most participants also had unfavorable cervical mucus (n = 39/51; 76%). 6 Overall, 94% had full protection against pregnancy, either through lack of ovulation (n = 9), unfavorable mucus (n = 14), or both (n = 25). The remaining 3 participants ovulated and had intermediate mucus scores; ultimately, these participants were considered to have medium protection against pregnancy.…”