Progesterone and is responsible for approximately 70% of cytochrome P450-mediated progesterone metabolism. Other routes include 6α-, 16α-, and 16β-hydroxylation. However, treatment of women with ketoconazole, a strong CYP3A4 inhibitor, had minimal effects on progesterone levels, producing only a slight and non-significant increase, and this suggests that cytochrome P450 enzymes play only a small role in progesterone metabolism. In women, progesterone levels are relatively low during the preovulatory phase of the menstrual cycle, rise after ovulation, and are elevated during the luteal phase, as shown in diagram below. Progesterone levels tend to be less than 2 ng/mL prior to ovulation, and greater
Progesterone vaginal ring Progesterone vaginal ring Progesterone vaginal ring, also known as progesterone-only vaginal ring, is a form of vaginal ring used for birth control when breastfeeding. Use can begin at four weeks and continue for at least up to a year following childbirth. Failure rates with usual use is about 1.5 per 100 women. It is used within the vagina with one ring lasting three months. The woman is able to place and remove the ring herself. Side effects include vaginal discharge and pain with urination. It does not appear to be associated with serious side effects. With use menstrual periods often