Comparison 2. Adult ‐ Metformin versus OCP (Hormonal parameters).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
2.1 Serum total testosterone (nmol/L)	17	818	Mean Difference (IV, Fixed, 95% CI)	0.39 [0.32, 0.47]
2.1.1 BMI ≤ 25 kg/m2	9	454	Mean Difference (IV, Fixed, 95% CI)	0.48 [0.38, 0.57]
2.1.2 BMI > 25 kg/m2< 30 kg/m2	4	220	Mean Difference (IV, Fixed, 95% CI)	0.21 [0.07, 0.35]
2.1.3 BMI ≥ 30 kg/m2	3	119	Mean Difference (IV, Fixed, 95% CI)	0.42 [0.11, 0.74]
2.1.4 Mean BMI not stated	1	25	Mean Difference (IV, Fixed, 95% CI)	‐0.69 [‐2.02, 0.64]
2.2 Free androgen index (FAI) (%)	10	433	Mean Difference (IV, Fixed, 95% CI)	3.95 [3.32, 4.58]
2.2.1 BMI ≤ 25 kg/m2	4	204	Mean Difference (IV, Fixed, 95% CI)	4.48 [3.56, 5.40]
2.2.2 BMI > 25 kg/m2< 30 kg/m2	3	110	Mean Difference (IV, Fixed, 95% CI)	3.06 [2.14, 3.97]
2.2.3 BMI ≥ 30 kg/m2	3	119	Mean Difference (IV, Fixed, 95% CI)	7.12 [4.46, 9.79]