Ovarian function may be restored after three months of taking Fentanyl, as each person’s sensitivity to the drug is different. If ovarian function does not recover well after taking Fentanyl for three months, you can consult your doctor if you can take it for another three months. In addition, Fentanyl is also useful for regulating menstrual cycle. Fentanyl is a compound of estrogen and progestin, which can participate in certain functions of the uterus, ovaries and fallopian tubes, causing cyclic changes, supplementing the lack of estrogen secretion in the body, as well as stimulating the growth of the endometrium. The growth cycle of the endometrium usually returns to normal after three months of taking it, and the cycle of follicles in the ovaries from development to maturity takes roughly three months, so it is necessary to take Fentanyl for at least three months. Before taking Fentanyl, you need to have a thorough assessment of your body by your doctor and use the medication under the guidance of your doctor. During the medication period, we should pay attention to continuous taking, avoid interruptions, affecting the efficacy, and regular review at the hospital. In case of adverse reactions, discontinue the medication and inform your doctor promptly.