D-Chiro-Inositol
TL;DR
Specific isomer of inositol that works alongside myo-inositol
Moderate evidence for improving insulin signaling in metabolic syndrome
Crucial for the 'Inositol Ratio' in PCOS (40:1 Myo to D-Chiro)
Excellent safety profile
Cost: ~$12-20/month
Best for: PCOS, metabolic syndrome, high-androgen states
What it is
D-Chiro-Inositol (DCI) is another form of inositol. While Myo-inositol is involved in glucose uptake, DCI is primarily involved in glucose storage and glycogen synthesis. In a healthy body, Myo-inositol is converted into DCI as needed.
In states like PCOS or Metabolic Syndrome, this conversion process is often broken. Supplementing with DCI helps ensure the body can properly manage insulin and, in women, helps regulate the production of androgens (like testosterone).
What the research says
DCI's evidence is strong when used correctly. Insulin Action. Studies have shown that DCI supplementation improves insulin sensitivity and reduces glucose levels in women with PCOS. Androgen Reduction. DCI is specifically effective at lowering elevated testosterone levels, which often drive the symptoms of metabolic syndrome in women. The Ratio. Most experts recommend using it in a 40:1 ratio with Myo-inositol, as taking high doses of DCI alone can actually be counterproductive for egg quality in women.
D-Chiro-Inositol on Amazon
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Safety
Very safe. Similar to Myo-inositol, it is well-tolerated with minimal side effects beyond occasional GI upset.
Interactions
None significant. Safe to take alongside most medications.
Dosing
Standard Dose: 50-100 mg daily, usually as part of a 40:1 Myo:DCI blend (e.g., 2000mg Myo to 50mg DCI). Form: Best taken in a pre-blended capsule or powder to ensure the correct ratio.
Cost
Affordable. Typically $12-20 per month when bought as a blend.
The bottom line
D-Chiro-Inositol is the 'specialist' partner to Myo-inositol. It's essential for anyone tackling PCOS or deep-seated insulin resistance.
Sources for this page include published meta-analyses, systematic reviews, and NIH dietary supplement fact sheets. All claims reflect the evidence as of early 2026.
This is not medical advice. Consult your healthcare provider before starting any supplement, especially if you take medications.