PLOD1 and polycystic ovary syndrome: Treatment trials of metformin (an oral anti-hyperglycemic found to reduce androgen levels, improve insulin resistance, and restore menstrual frequency and fertility in many women with PCOS) also support alterations in ALLO levels as well as a dysregulation of the normal signaling pattern among GnRH, LH, ACTH, and ALLO, though not always in the same direction.