Önalan et al. (2005) found that metformin had the most pronounced effects on hirsutism and ovulatory regularity in lean hyperinsulinemic PCOS patients. Similarly, metformin had a greater capacity to reduce insulin, androgen and LH levels in those lean PCOS patients who were hyperinsulinemic based on their glucose-stimulated insulin secretion levels at baseline (Genazzani et al. 2007). Here, INS is linked to polycystic ovary syndrome.