inositol

Inositol is a naturally occurring sugar-like compound (a type of polyol) found in foods such as fruits, beans, grains, and nuts; its most common form is myo-inositol. The body also produces it, and it is involved in the way cells respond to certain signals, including insulin. It is sold as a dietary supplement, often as myo-inositol on its own or combined with D-chiro-inositol.

Strong, government-reviewed evidence supporting inositol is limited. For depression specifically, the NCCIH states that data from current scientific research do not support using inositol to treat depression; a 2014 meta-analysis of seven randomized controlled trials (242 participants) cited by NCCIH found no significant treatment effect versus placebo. The same review noted only a possible trend toward benefit for depressive symptoms in people with premenstrual dysphoric disorder (PMDD) — a trend, not a proven effect. Other popular uses such as PCOS, metabolic goals, and gestational diabetes are areas of ongoing research and are not addressed by these NCCIH materials, so they should be viewed as reasons people take inositol rather than benefits confirmed by these authoritative sources.

There is no official NIH-established recommended dose for inositol as a supplement, and the amounts in commercial products vary widely. Because the supporting evidence is limited and inositol is sometimes taken alongside medications or during pregnancy, speak with a doctor, pharmacist, or other qualified clinician before starting it, and do not use it in place of prescribed treatment.

According to NCCIH, there is little data on the safety and side effects of inositol, so its long-term safety is not well characterized. Anyone who is pregnant, breastfeeding, has a health condition, or takes prescription medicine should check with a clinician before use. Let your healthcare providers know about any supplements you take.

Reported side effects are generally mild and digestive. Research cited by NCCIH indicated that inositol was only marginally more likely than placebo to cause gastrointestinal upset, such as nausea, gas, and diarrhea, mainly at higher intakes. Stop and consult a clinician if you have a concerning or persistent reaction.

These authoritative government sources do not publish a detailed list of inositol drug interactions, so its interaction profile is not well established. Because inositol is involved in insulin-related cell signaling and is sometimes used for blood-sugar or hormonal concerns, people taking diabetes medications, fertility or hormonal treatments, or any prescription drug should check with a clinician or pharmacist before combining them with inositol.