The normal range of progesterone during menstruation is 0.99-4.83 nmol/L. The value of progesterone varies with the menstrual cycle, with the lowest value in the follicular phase, rising in the mid-luteal phase, and the highest value before the menstrual period after ovulation. Usually progesterone reaches its highest level about three days before menstruation, and then it decreases and withdraws, thus causing the onset of menstruation after the endometrial lining is stripped. For women with insufficient luteal function, often detected during ovulation, progesterone will be lower than normal because progesterone does not reach its peak and will affect the endometrial shedding, which will also lead to delayed menstruation or reduced menstrual volume. low progesterone level will also affect ovulation function, leading to infertility in women. low progesterone can be supplemented with progesterone through intramuscular progesterone injection.