While metformin is generally safe during breastfeeding, switching from insulin (NovoRapid and Levemir) back to oral medications like Glucoryl M1 (glimepiride and metformin) requires careful evaluation. Some oral medications can pass into breast milk and potentially affect your baby's blood sugar, which is why insulin is often preferred during this time. Your doctor will need to assess your current blood sugar control and overall health before making any changes. Please consult your healthcare provider before adjusting your treatment.