DChiroInositol

D-chiro-inositol (DCI) is one of the nine stereoisomers of inositol, a cyclohexanehexol that occurs naturally in plants and animals. In humans, DCI can be formed from myo-inositol by tissue-specific epimerization and is found in several organs, including the liver, kidney, muscle, and ovaries. It is a component of inositol phosphoglycans that participate in insulin signal transduction and cellular metabolism.

In insulin signaling, DCI-containing inositol phosphoglycans are proposed to act as secondary messengers, contributing to glucose uptake and metabolism. DCI is also implicated in ovarian physiology, where tissue-specific balance with myo-inositol is thought to influence follicular development and ovulation.

Clinical research focuses largely on polycystic ovary syndrome (PCOS) and insulin resistance. Some studies indicate that DCI, alone or in combination with myo-inositol, can improve insulin sensitivity, lower hyperinsulinemia, and may restore ovulatory function in PCOS. Many protocols use a mixture of myo- and D-chiro-inositol, often in ratios intended to mimic physiological tissue balance (commonly around 40:1, myo- to DCI). DCI doses in trials typically range from about 200 to 600 mg per day, while myo-inositol doses are commonly 2–4 g per day. High-dose DCI alone has, in some cases, been associated with reduced ovarian response or impaired oocyte quality, leading researchers to favor lower doses or ratio-based approaches.

Safety and regulation: DCI is widely available as a dietary supplement in many countries, but it is not approved as a drug for medical indications by major regulators. Adverse effects are generally mild, such as gastrointestinal symptoms. As with other supplements, use during pregnancy or in medical conditions should involve consultation with a healthcare professional.