The issue of PCOS patients over-converting MI to DCI, is identified as a key mechanism underlying the “D-chiro-inositol (DCI) ovarian paradox.”
Here’s what the research reveals:
The report describes how PCOS patients with hyperinsulinemia commonly present “increased levels MI to DCI epimerisation, leading to an MI deficiency in the ovaries, resulting in impaired folliculogenesis, anovulation, and decreased oocyte quality” . This over-conversion is mediated by insulin-stimulated epimerase activity, where “insulin can stimulate enzymatic activity in the ovaries, leading to an increase in the DCI/MYO conversion rate” .
The research emphasises that different tissues have vastly different inositol requirements. The physiological ovarian MI/DCI ratio is 100:1, which is “much higher” than the serum ratio of 40:1, “with a greater need for MI due to its role in FSH signaling” . This suggests that ovaries are particularly vulnerable to MI deficiency when conversion rates increase.
Multiple studies describe what’s termed the “D-chiro-Ins ovarian paradox” . In PCOS ovaries, “increased epimerase activity leads to local Myo-Ins deficiency” which “may adversely affect glucose uptake and metabolism of both oocytes and follicular cells” . This creates a situation where the ovary becomes depleted of the specific inositol form it needs most.
The research provides clinical evidence that this over-conversion is problematic. Isabella et al. demonstrated that “increasing DCI dosage progressively worsens oocyte quality and ovarian response” in non-insulin-resistant PCOS patients . This suggests that adding more DCI (the end product of conversion) when conversion is already excessive can further harm ovarian function.
The over-conversion has specific functional consequences because MI and DCI serve different roles: “MI increases glucose cellular uptake and D-chiro-Ins is involved in glycogen synthesis” . Since ovaries require glucose uptake for proper function rather than glycogen storage, the shift toward DCI production impairs ovarian metabolism.
This over-conversion research suggests that PCOS treatment should focus on restoring MI availability rather than providing more DCI. The research indicates that “myo-inositol treatment rather than D-chiro-inositol is able to improve oocyte and embryo quality during ovarian stimulation protocols” in euglycemic PCOS patients , supporting the idea that correcting MI deficiency is more important than adding DCI. The research comprehensively addresses this over-conversion issue as a central mechanism explaining why standard 40:1 ratios may be inappropriate for many PCOS patients, particularly those undergoing fertility treatments.
Based on the research report, here are the key citations specifically relating to the over-conversion paradox:
V. Unfer et al., 2016 – This is the most comprehensive source, describing:
O. Pustotina et al., 2024 – Provides detailed mechanistic explanation:
R. Isabella et al., 2012 – Describes the clinical paradox:
N. Mendoza et al., 2017 – Supports the conversion mechanism:
V. Unfer et al., 2011 – Provides clinical evidence of the paradox effects in euglycemic PCOS patients undergoing ICSI
M. Nordio et al., 2019 – Shows that “too much DCI causes a loss of beneficial effects at the reproductive level”
It makes total sense to want a clear, simple way to explain PCOS—especially because it can feel confusing and a bit overwhelming when you’re living it. You’re doing a really good thing by getting informed and bringing your partner into it. It has effects on partners in the relationship, not just yourself.
PCOS (Polycystic Ovary Syndrome) is a very common hormone condition that affects how the ovaries work.
Here’s the simplest way to describe it:
1) “My ovaries have lots of follicles, but they don’t always release an egg”
People with PCOS often, but not always, have many small follicles (tiny “egg sacs”) in the ovaries.
They can look like “cysts” on an ultrasound, but they aren’t usually true cysts—it’s more like the ovaries are “stocked up,” and the eggs don’t mature and release as regularly.
What that can feel like day-to-day: periods that are irregular, unpredictable, or missing.
2) “Ovulation can be irregular—so timing is harder”
Because ovulation (releasing an egg) may happen less often or unpredictably, cycles can be longer or inconsistent.
This is one reason PCOS can make it harder to conceive, not because pregnancy is impossible, but because ovulation is harder to predict.
3) “Insulin resistance is often part of the picture”
A lot of people with PCOS have insulin resistance, meaning the body needs more insulin than usual to manage blood sugar. Higher insulin can then nudge the ovaries to make more androgens (hormones like testosterone).
What that can feel like: energy dips, intense cravings, feeling “wired then tired,” or trouble feeling stable between meals (everyone’s experience varies).
4) “Higher androgens can show up in visible ways”
Those higher androgens can contribute to things like:
5) “It can affect mood too—and it’s not ‘all in your head’”
Living with fluctuating hormones, fatigue, and uncertainty can affect mood, anxiety, motivation, and self-confidence. That’s a real part of PCOS for many people.
“PCOS is a hormone condition where my ovaries don’t always release an egg regularly. That can make my periods unpredictable and can affect fertility timing. A lot of PCOS is linked to insulin resistance, which can also affect energy and cravings. It’s manageable, but it’s a real physical thing—not just stress—and support helps.”
Gentle, grounded reassurance
PCOS is common (often cited around 6–15% of reproductive-age women, depending on criteria), and there are multiple ways to support it—usually starting with lifestyle foundations, and sometimes medication or targeted supplements with a clinician’s guidance.
For in depth review we suggest you look at Teede HJ, et al. International evidence-based guideline for the assessment and management of PCOS (2018; updated 2023). Human Reproduction / Monash University guideline group.
Inositol begins improving PCOS symptoms