D-Chiro-Inositol
Also known as: DCI, D-chiro inositol, chiro-inositol, D-chiroinositol
D-chiro-inositol is a minor inositol isomer produced from myo-inositol by an insulin-dependent epimerase. It is involved in insulin signaling for glycogen synthesis and in ovarian steroid handling, and it is used almost exclusively in women's hormone and metabolic formulas, most often as the minor partner in a 40:1 myo-inositol to D-chiro-inositol blend that mirrors the plasma ratio. Reviews caution that high D-chiro-inositol alone may work against ovarian function, so doses are kept in the low hundreds of milligrams.
Research summary
Incorporated into inositol phosphoglycan mediators that activate glycogen synthase and pyruvate dehydrogenase downstream of the insulin receptor; modulates aromatase and androgen synthesis in the ovary.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| — | 100–600 mg | — | — |
Doses are mg D-chiro-inositol. In the ratio study by Nordio 2019, 4 g/day of combined inositols at 40:1 delivers about 100 mg/day D-chiro-inositol, the ratio that performed best for ovulation; ratios with more D-chiro-inositol performed worse. Stand-alone products of several hundred milligrams exist, but the 600 mg ceiling here reflects market practice rather than a verified dose-finding trial, and no dose_max_studied is set. Usually taken with myo-inositol, split across the day. No UL.
Standardization: ≥98% D-chiro-inositol
Source material: carob pod extraction or conversion from myo-inositol
Forms of Inositol
| Form | Typical dose | Element % | Formats | Price |
|---|---|---|---|---|
| D-Chiro-Inositol | 100–600 mg | — | Capsule, Powder, Tablet | high |
| Myo-Inositol | 2–4 g | — | Powder, Capsule, Tablet | low |
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Water-soluble and mildly sweet; small doses fit easily in capsules or blended powders.
Formulation notes
Almost always formulated with myo-inositol at 40:1. Reviews advise against high stand-alone doses in PCOS formulas because of possible negative effects on ovarian function.
Sources
- The 40:1 myo-inositol/D-chiro-inositol plasma ratio is able to restore ovulation in PCOS patients: comparison with other ratios. (Nordio M, 2019)PubMed
- D-Chiro-inositol and PCOS: between myth and reality. The never-ending story. (Cianci A, 2022)PubMed
- Myo-inositol vs. D-chiro inositol in PCOS treatment. (Formuso C, 2015)PubMed
Related ingredients
Myo-Inositol
OtherMyo-inositol is a sugar alcohol the body makes from glucose and the most abundant inositol isomer in cells, where it forms the backbone of phosphatidylinositol signaling lipids and the second messengers that relay insulin and hormone signals.
Typical: 2–4 g
Berberine HCl
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Typical: 900–1,500 mg
Chromium Picolinate
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Typical: 200–500 mcg
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Typical: 18–30 mg
Psyllium Husk
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Typical: 5–10 g