Table 5. General characteristics of included studies.

RCT: randomized controlled trial; NN-RCT: non-randomized clinical trial; AMSTAR: Assessment of multiple systematic reviews; JBI: Joanna Briggs Institute; MI: myoinositol; MET: metformin; DCI: D-chiro-inositol; BMI: body mass index; WHR: waist-to-hip ratio; FBS: fasting blood sugar; PMBS: post-meal blood sugar; LH: luteinizing hormone; FSH: follicle-stimulating hormone; AFC: antral follicle count; HOMA-IR: homeostatic model of assessment for insulin resistance; AE: adverse event; PL: prolactin; USG: ultrasonogram; IR: insulin resistance; SHBG: steroid hormone binding globulin; DHEA: dehydroepiandrosterone; 17-OH-P: 17-hydroxy progesterone

Author	Year of Publication	Study Design	Quality Appraisal Tool	Number (No ) of Subjects/Studies	Intervention	Duration	Outcomes Measured
Angik et al. [26]	2015	RCT	Cochrane risk of bias assessment tool	(No = 100) MI: 50 MET: 50	MI 1g b.i.d Vs. MET 500mg b.i.d	Six months	Menstrual abnormalities, hirsutism, acne, BMI, WHR, FBS, PMBS, post-meal insulin, testosterone, LH, LH/FSH ratio, mean ovarian volume, AFC, fasting insulin, HOMA-IR, pregnancy, AE
Awalekar et al. [43]	2015	NN-RCT	JBI checklist	(No = 67) MI: 32 MET: 35	MI 2g b.i.d, Folic acid 5mg/day Vs. MET 500mg t.i.d	Three months	BMI, HOMA-IR, LH/FSH ratio
Nehra et al. [33]	2016	RCT	Cochrane risk of bias assessment tool	(No = 60) MI: 30 MET: 30	MI 1g b.i.d Vs. MET 500mg t.i.d	24 weeks	Regularity of menstrual cycle, hirsutism, weight changes, AE
Nehra et al. [34]	2017	RCT	Cochrane risk of bias assessment tool	(No = 60) MI: 30 MET: 30	MI 1g b.i.d Vs. MET 500mg t.i.d	24 weeks	body weight, BMI, waist circumference, hip circumference, WHR
Nehra et al. [35]	2017	RCT	Cochrane risk of bias assessment tool	(No = 60) MI: 30 MET: 30	MI 1g b.i.d Vs. MET 500mg t.i.d	24 weeks	Insulin, FSH, LH, LH/FSH ratio, testosterone, HOMA-IR, glucose/insulin ratio, lipid profile
Nabi et al. [32]	2018	RCT	Cochrane risk of bias assessment tool	(No = 63) MI: 32 MET: 31	MI 2g/day Vs. MET 500mg b.i.d	16 weeks	Weight, BMI, WHR, FBS, PMBS, fasting insulin, LH, LH/FSH ratio, testosterone, PL, hirsutism, progesterone, USG characteristics, AE
Facchinetti et al. [40]	2019	Meta-analysis	AMSTAR 2 checklist	Six RCTs with (No = 355) MI: 177 MET: 178	MI 2-4g/day Vs. MET 1.5-2g/day	12-24 weeks	Insulin, HOMA-IR, testosterone, androstenedione, SHBG, BMI, AE
Thalamati [39]	2019	RCT	Cochrane risk of bias assessment tool	(No = 200) MI: 100 MET: 100	MI 550mg + DCI 13.8mg b.i.d Vs. MET 500mg t.i.d	24 weeks	Menstrual cycle regulation, hirsutism, insulin, glucose, DHEA, LH/FSH ratio, testosterone, HOMA-IR, glucose/insulin ratio
Agarwal et al. [25]	2021	RCT	Cochrane risk of bias assessment tool	(N0 = 50) MI: 25 MET: 25	MI 1g b.i.d Vs. MET 850mg b.i.d	Six months	menstrual abnormality, acne, hirsutism, USG characteristics, LH, FSH, LH/FSH ratio, testosterone, SHBG, lipid profile, FBS, PMBS, fasting insulin, post-meal insulin, glucose/insulin ratio, HOMA-IR, AE
Bahadur et al. [28]	2021	RCT	Cochrane risk of bias assessment tool	(No = 72) MI+MET: 36 MET: 36	MI 550mg+DCI 150mg+MET 500mg b.i.d Vs. MET 500mg b.i.d	Six months	menstrual cycle irregularity, hirsutism, acne, waist circumference, hip circumference, WHR, BMI, lipid profile, FBS, PMBS, fasting and post-meal insulin, HOMA-IR, LH/FSH ratio, serum testosterone, DHEA
Azizi Kutanaei et al. [41]	2021	Meta-analysis	AMSTAR 2 checklist	Nine studies: seven RCTs, 1 NN-RCT, and one retrospective study (No = 684) MI: 331 MET: 353	Not included	12 weeks- six months	Menstrual irregularity, LH, FBS, FSH, LH/FSH, HOMA-IR, testosterone, prolactin, DHEA, 17-OH-P (17-hydroxy progesterone), androgen, estradiol, SHBG, ovarian volume, insulin
Zhang et al. [42]	2022	Meta-analysis	AMSTAR 2 checklist	Nine RCTs with (No = 612) MI: 306 MET: 306	MI 1-4g/day +/- 40-200 mcg folic acid/day Vs. MET 500-1500mg/day +/- folic acid 200mcg/day	three-six months	BMI, WHR, androstenedione, testosterone, DHEA, SHBG, lipid profile, FBG, fasting insulin, HOMA-IR, AE