Additionally, AMH levels significantly slid down in PCOS patients with no more than 6 months metformin treatment [SMD − 1.38, 95% CI − 2.18 to − 0.58, P = 0.0007], or with no more than a dose of 2000 mg/day [SMD -0.70, 95% CI -1.11 to -0.28; P = 0.001]. Here, AMH is linked to polycystic ovary syndrome.