Inositol vs metformin for PCOS
Two ways to lower the insulin that drives PCOS (now officially PMOS). One you can buy today. One your doctor prescribes. Here is how they actually compare.
Evidence-based · Sources cited · Updated July 2026
Reviewed vs the 2023 international PCOS guideline · Jul 2026
In head to head trials, inositol works about as well as metformin. It has fewer side effects. The catch is that its evidence base is smaller, so the guideline stays cautious.
At a glance
More dots is better. Both lower insulin, the root driver in most PCOS.
Why inositol still is not the standard
If it matches metformin, why not switch everyone? Because the inositol trials are small and use different doses. Metformin has decades of use behind it. So inositol is a low-risk place to start. It is not yet a guaranteed swap for a prescription.
Can you take both?
Sometimes. Some clinicians combine them for an added effect on insulin. Metformin is a prescription, so this is a conversation with your doctor.
Inositol takes 3 months to show. Know if it is working.
leto tracks whether your protocol is actually moving your numbers, not just your hopes.
Keep reading
Sources
- Greff D. et al., inositol vs metformin in PCOS. PMC9786218
- 2023 International Evidence-Based Guideline for PCOS. PMC10505534
- Inositol in PCOS, updated review. Gynecol Endocrinol 2024
Educational, not medical advice. Metformin is prescription only. Talk to a clinician before you start, stop, or combine treatments.