If the
FSH level is as low as 4, ask your doctor to check a blood test for Estrdiol at the same time. It is possible your body is making
estrogenHormone replacement therapy and that is lowering the FSH level. However, until menopause is reached, FSH levels do fluctuate in a rather wide range. However, 4 is not typical and suggests something is not usual and should be explored further. At the very least, send the blood to another lab at the same time so it can be seen if the lab testing is just off. That is unlikely, but one explanation.
Machelle M. Seibel, MD