Metformin for PCOS & Insulin Resistance – What Does It Actually Do Long-Term? Any Risks to Normal Glucose Function?

Hi everyone. I have been diagnosed with PCOS for about 5 to 6 years now and have been taking metformin for a year or two as well. I also take inositol and berberine (500 mg) currently.

Before starting berberine, my A1c was 5.8 (so borderline prediabetic range). My B12 was in the 160s probably due to metformin and I had numbness/tingling in my feet, so now I take B12 supplements daily (empty stomach in the morning).

I understand that metformin lowers blood glucose and improves insulin sensitivity. But I’m trying to understand the long-term metabolic impact:

•	Does metformin change the body’s natural glucose regulation over time?

•	Does it affect pancreatic function or insulin production long-term?

•	If someone takes it for years for PCOS/insulin resistance (not diabetes), does it impair “normal” functioning?

•	Is combining metformin + berberine risky in terms of hypoglycemia? I haven’t experienced low blood sugar symptoms, but I’ve read that berberine can lower glucose significantly.