4mm uterine lining with progesterone will not come to menstruation is not necessarily, the probability will not lead to menstruation, or may lead to menstruation but the amount is small.
Progesterone belongs to the progesterone class of drugs, after the use of stopping the drug, can lead to endometrial shedding bleeding, that is, menstruation, therefore, the progesterone usually need to be in the uterine lining to reach a certain thickness, in order to work.
A thin endometrium may indicate that a woman has low levels of estrogen and progesterone or endometrial pathology, such as adhesions in the uterine cavity. Different treatments are available for different causes, such as estrogen-progestogen cycles for low hormone levels, or hysteroscopy for adhesions in the uterine cavity.
Patients with thin endometrium and prolonged absence of menstruation can be caused by a variety of reasons, such as hypothalamic or pituitary lesions that may lead to amenorrhea. Therefore, patients with abnormal menstruation should consult a doctor in a timely manner, complete the relevant examinations, and under the guidance of a professional doctor to clarify the cause of the disease and target treatment.