15 years old menstrual dribbling, progesterone 0.56nmol/L may not be a normal value, the value of progesterone during menstruation is about 0.99 ~ 4.83nmol/L. Progesterone is one of the sex hormones, reflecting the level of female endocrine an important indicator, due to the different testing methods and quality control standards used by each hospital, the normal range of the test may vary. The value of progesterone during menstruation is about 0.99~4.83nmol/L, and 0.56nmol/L of progesterone is on the low side. Low progesterone will lead to endocrine imbalance in the body, resulting in the symptom of irregular menstruation in women. If a 15 year old girl’s menstrual flow is caused by insufficient progesterone in her body, she can be treated by supplementing the appropriate progesterone under the guidance of her doctor, such as progesterone, dydrogesterone and other medications, which can increase the level of progesterone in the blood, and make the endometrium change from proliferative to secretory phase, which can improve the symptoms of menstrual flow. Fifteen-year-old women may not have had their first menstrual period for a long time, and there may be other reasons for observing irregular menstruation, so it is recommended to go to the hospital for a clear diagnosis and then treat the cause.