A recently published article reports on a phase I/II pharmacokinetic and pharmacodynamic clinical trial of two levonorgestrel (LNG)-only contraceptive patches. The transdermal patches deliver a daily dose of either 40 mcg or 75 mcg and are intended for 7-day use. Study participants were randomized to receive either the high-dose or low-dose weekly patch for 11 consecutive weeks.
The researchers assessed serum LNG concentration, cervical mucus score, and frequency of ovulation among participants. They found that LNG concentration levels were low and ovulation occurred for a majority of the women. In addition, they did not find an association with a reduction in cervical mucus score. The results of this clinical trial indicate that these LNG-only patches may not be an effective contraceptive method and the authors suggest that further research be done for contraceptive patches with a higher LNG dosage.