D-Chiro-Inositol

D-Chiro-Inositol (DCI) is a sugar-like molecule that helps carry the insulin signal inside cells. The body makes it from a related molecule, myo-inositol. An enzyme that responds to insulin drives this step.¹ Each form has its own role. The myo-inositol signal helps cells take in glucose. The DCI signal helps cells store glucose as glycogen.¹ In the ovary, the DCI signal helps insulin drive theca cells to make androgens. DCI can also lower the action of aromatase. This enzyme turns androgens into estrogen.¹

In polyendocrine metabolic ovarian syndrome (PMOS), formerly polycystic ovary syndrome (PCOS), muscle and liver often respond poorly to insulin. The ovary keeps its normal response.¹ The body makes extra insulin to make up for the poor response. In the ovarian DCI paradox, that extra insulin likely drives the ovary to make too much DCI.¹ The result is more insulin-driven androgen from the ovary. This excess is a key driver of hyperandrogenism.

In a placebo-controlled trial, women with PMOS / PCOS who took DCI responded better to insulin. Their testosterone fell, and far more of them ovulated.² Higher amounts can have the opposite effect. As the amount of DCI rises, its benefits fade. Too much DCI around the egg has been linked to poorer embryo quality.¹ For this reason, reviews favor myo-inositol paired with DCI, rather than DCI alone. The favored ratio is close to the natural blood levels of the two forms.¹

RRM clinicians may consider ratio-based inositol supplementation as a nutritional support option for women with PMOS / PCOS, adjusted under clinical supervision.