D-Chiro-Inositol (DCI) is generally considered safe for most people when taken at appropriate doses, but like any supplement, it can have adverse effects, especially if misused or taken in high doses. Here’s a detailed overview:
1. Gastrointestinal Effects
- Nausea
- Diarrhea
- Abdominal discomfort or bloating
These are among the most commonly reported side effects and are usually mild. Taking D-Chiro-Inositol with food can reduce these symptoms.
2. Hypoglycemia Risk
- D-Chiro-Inositol enhances insulin sensitivity, so in people taking antidiabetic medications, there is a potential risk of low blood sugar.
- Symptoms may include dizziness, sweating, or fainting.

3. Hormonal Effects (in women)
- D-Chiro-Inositol influences ovarian function and androgen levels.
- In rare cases, inappropriate dosing may disrupt menstrual cycles or hormonal balance, especially if combined with Myo-Inositol in non-recommended ratios.
4. Potential for Over-supplementation
- High doses of D-Chiro-Inositol (far above typical supplement levels of 600–1200 mg/day) have been linked in some studies to reduced oocyte quality in women undergoing IVF.
- Long-term effects at high doses are not well studied, so caution is advised.
5. Allergic Reactions
- Extremely rare, but possible. Signs may include rash, itching, or swelling.
6. Interactions
- D-Chiro-Inositol may interact with insulin, metformin, or other blood sugar-lowering drugs, enhancing their effect.
- Caution is needed in people with diabetes or hormonal disorders.

Summary
For most healthy adults, D-Chiro-Inositol is well tolerated, but gastrointestinal issues and mild hormonal effects are the main concerns. People on blood sugar medications or undergoing fertility treatments should use it under medical supervision.
