What do systematic reviews say?

Metformin combined with clomiphene citrate vs clomiphene

Metformin combined with clomiphene citrate may leads to higher ovulation rate per woman compared with clomiphene citrate alone (low certainty).

• Metformin for ovulation induction (excluding gonadotrophins) in women with polycystic ovary syndrome 2019 · Cochrane Headline outcomes only
  OR 1.65 [1.35, 2.03]
  22 studies · 1601 participants
  Low
• Insulin‐sensitising drugs (metformin, rosiglitazone, pioglitazone, D‐chiro‐inositol) for women with polycystic ovary… 2017 · Cochrane Headline outcomes only
  OR 1.57 [1.28, 1.92]
  21 studies · 1624 participants
  Moderate