Inositol or Metformin? Rethinking Insulin Resistance in PCOS Care for Women with Obesity

Dr. Lakshmi Nagendra, Associate Professor, Department of Endocrinology, JSS Medical College, Mysore

Targeting insulin resistance with metformin or inositols is central to PCOS care, with inositols offering a gentler, patient-friendly alternative in selected women.

Polycystic ovary syndrome (PCOS) remains the most common endocrine disorder affecting women worldwide, yet its management continues to evolve as our understanding of its metabolic roots deepens. At the centre of PCOS lies insulin resistance—a driver of hyperandrogenism, ovulatory dysfunction, and long-term cardiometabolic risk. Addressing this core abnormality is key to improving both reproductive and metabolic outcomes.

Metformin has long been the cornerstone of insulin-sensitising therapy in PCOS. Its benefits in improving menstrual regularity, reducing androgen levels, and lowering the risk of ovarian hyperstimulation are well recognised, particularly in overweight and insulin-resistant women. However, gastrointestinal side effects and variable patient acceptance have encouraged the search for gentler alternatives.

Inositol derivatives, especially myo-inositol (MYO) and D-chiro-inositol (DCI), have emerged as promising options. These naturally occurring molecules play a vital role in intracellular insulin signalling. Evidence suggests that MYO improves insulin sensitivity, supports follicular maturation, and enhances oocyte and embryo quality, while carefully balanced MYO–DCI combinations may further optimise ovarian response. Importantly, their safety profile is favourable, making them attractive for long-term use.

When it comes to assisted reproduction, inositols appear to reduce gonadotropin requirements and improve ovarian response, though gains in live birth rates remain inconsistent. Overall, current data suggest that MYO and DCI can complementor, in selected cases, substitute for metformin in PCOS management. The challenge ahead lies in refining patient selection, dosing ratios, and expectations, moving towards more personalised, metabolism-focused care.

(Source: Kaya C. Metformin, myo-inositol and D-chiro-inositol use and ART outcomes in women with PCOS: current results and future perspectives. Journal of Health Sciences and Medicine. 2026 May 1;9(1):243-52.)