When you start digging into supplements for PCOS, one name keeps coming up again and again: inositol. And for good reason. It’s one of the most researched, safe, and effective options out there for women with PCOS, especially if insulin resistance or irregular cycles are part of the picture.

But while PCOS is the main reason most women look at inositol, research is now showing it may have benefits beyond fertility and hormone balance. In particular, it’s being studied for liver health – something that’s often overlooked but deeply connected to PCOS and metabolic health.

Here is some of what science tells us:

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PCOS and Inositol

Why Inositol Works So Well in PCOS

PCOS is one of the most common hormone conditions in women, affecting about 1 in 10. It’s not just about irregular cycles or cysts on the ovaries – insulin resistance, excess androgens (male-type hormones), acne, and weight struggles are all part of the picture for many women.

That’s where inositol fits in. There are different forms (called isomers), but the two most important for PCOS are myo-inositol (MI) and D-chiro-inositol (DCI).

Here’s what they do:

• Myo-inositol (MI): helps the ovaries respond to FSH, which is key for egg development, ovulation, and regular cycles. It also supports estrogen production.
• D-chiro-inositol (DCI): helps with insulin sensitivity and lowering androgens – but too much can actually reduce estrogen and harm egg quality.

This is why the 40:1 ratio of MI to DCI is now considered the “sweet spot.” It mimics the balance we see in healthy ovaries and has been shown in studies to restore ovulation and improve fertility (Nordio et al., 2019).

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What the Research Says

The evidence is strong that inositol can help with:

• Ovulation & fertility: Women taking myo-inositol often see cycles become more regular, and ovulation return (Sharon et al., 2024).
• Androgens: Both MI and DCI can lower testosterone levels, which helps with acne, hair growth, and hair thinning (Unfer et al., 2023).
• Insulin resistance: Inositol improves the way the body handles glucose and insulin, which supports weight management and lowers long-term risk of type 2 diabetes (Kamenov et al., 2020).

In 2024, researchers (Fedeli et al.) even showed that giving ovaries the 40:1 mix in lab and mouse studies restored normal hormone balance – less excess androgens, better estrogen production.

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Not All PCOS Is the Same

One important point: not every woman with PCOS responds the same way to inositol.

• Women with high androgens (the most common PCOS types A, B, C): respond really well – better cycles, better hormone balance, improved insulin sensitivity.
• Women without high androgens (PCOS type D): the response isn’t always as strong, and some studies suggest little to no effect (Unfer et al., 2023).

That doesn’t mean it’s not worth trying – but it shows PCOS isn’t one-size-fits-all, and neither is supplementation.

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How to Use Inositol Safely

The good news? Inositol is very safe, with very few side effects reported. Practical tips:

• Myo-inositol on its own: usually effective at 2–4 g per day.
• Myo + D-chiro (40:1 ratio): considered the gold standard for PCOS.
• Avoid high-dose DCI on its own: it can harm egg quality if overdone.

For most women, the 40:1 formula is the most balanced and effective option.

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Beyond PCOS: Inositol and the Liver

So that’s PCOS covered – but here’s where it gets interesting. Researchers are now looking at inositol’s role in liver health, especially non-alcoholic fatty liver disease (NAFLD).

Why does this matter? Because many women with PCOS also have NAFLD without realising it. Both conditions are driven by insulin resistance and metabolic dysfunction, so the overlap makes sense.

How Inositol Helps the Liver

Here’s what the science suggests:

• Reduces liver fat: inositol helps lower triglycerides and cholesterol inside the liver (Pani et al., 2020).
• Protects against damage: it improves antioxidant defences and reduces inflammation (Yang et al., 2022).
• Improves insulin signalling: it activates key pathways (like AMPK and SIRT-1) that help the liver burn fat instead of storing it (Arefhosseini et al., 2024).

What Studies Show So Far

• In animal studies, inositol reduced fat build-up in the liver and protected against liver damage caused by a high-fat diet (Yang et al., 2022).
• In humans, a 2023 trial found myo-inositol improved liver enzymes, cholesterol, and insulin sensitivity in obese patients with NAFLD (Arefhosseini et al., 2023).
• Another 2024 study confirmed that these benefits are linked to activation of the SIRT-1 pathway, which is like a “metabolic switch” for better liver function.

This is still early-stage research, but it’s exciting because it means inositol could help not just with PCOS but with the long-term liver health issues that often go alongside it.

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The Takeaway

If you have PCOS, inositol is one of the best-studied supplements you can use. It can improve ovulation, lower androgens, and help with insulin resistance – especially when taken in the right ratio (40:1 myo-inositol to D-chiro-inositol).

And while PCOS is the main reason women take inositol, we now know its benefits may go further – supporting liver health in people with NAFLD, which often overlaps with PCOS.

Right now, the evidence for PCOS is strong enough to confidently recommend inositol as part of a management plan. For liver health, the research is promising but still developing.

Either way, it’s a safe, well-tolerated supplement with potential benefits that go beyond hormones and fertility – making it one of the most exciting tools we have in women’s health. For more tips and lifestyle posts follow Sarahcurranfitpro on Instagram.

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References

Arefhosseini, S., et al., 2023. Myo-inositol supplementation improves cardiometabolic factors, anthropometric measures, and liver function in obese patients with non-alcoholic fatty liver disease. Frontiers in Nutrition.

Arefhosseini, S., et al., 2024. Myo-inositol supplementation in obese patients with non-alcoholic fatty liver disease: Assessment of sirtuin-1 pathway, atherogenic and hematological parameters. Journal of Functional Foods.

Facchinetti, F., et al., 2020. Inositols in Polycystic Ovary Syndrome: An Overview on the Advances. Trends in Endocrinology & Metabolism.

Fedeli, V., et al., 2024. Inositol restores appropriate steroidogenesis in PCOS ovaries both in vitro and in vivo experimental mouse models. Cells.

Kamenov, Z., et al., 2020. Inositols in PCOS. Molecules.

Nordio, M., et al., 2019. The 40:1 myo-inositol/D-chiro-inositol plasma ratio is able to restore ovulation in PCOS patients. European Review for Medical and Pharmacological Sciences.

Pani, A., et al., 2020. Inositol and Non-Alcoholic Fatty Liver Disease: A Systematic Review. Nutrients.

Sharon, M.P., et al., 2024. The effectiveness of myo-inositol in women with polycystic ovary syndrome: A prospective clinical study. Cureus.

Unfer, V., et al., 2023. Treatment with myo-inositol does not improve the clinical features in all PCOS phenotypes. Biomedicines.

Yang, Q., et al., 2022. D-chiro-inositol facilitates adiponectin biosynthesis and activates the AMPKα/PPARs pathway to inhibit high-fat diet-induced obesity and liver lipid deposition. Food & Function.