DCI Treatment Causes Unexpected Hormonal Effects in Obese Women

study PMID: 40235665

Quick Summary: A study found that high doses of D-chiro-inositol (DCI), a supplement sometimes used for insulin resistance, caused unexpected hormonal changes in obese women following a specific diet. These changes, which included increased testosterone and menstrual irregularities, may have counteracted the intended benefits.

What The Research Found

Researchers looked at the effects of high-dose DCI on overweight and obese women with insulin resistance. They found that while the women were also following a healthy diet, the DCI seemed to cause some unexpected problems. Specifically, the women experienced hormonal imbalances, including increased testosterone levels and issues with their menstrual cycles. This suggests that high doses of DCI might not be beneficial and could even be harmful for some people.

Study Details

Who was studied: 45 overweight/obese women with insulin resistance.

How long: 12 weeks.

What they took: High-dose DCI (1,200 mg daily) along with a hypocaloric Mediterranean diet.

What This Means For You

If you're considering taking DCI, especially at high doses, it's important to talk to your doctor first. This study suggests that high doses of DCI might not be safe for everyone, particularly if you're already dealing with hormonal issues. It's crucial to understand the potential risks and benefits before starting any new supplement.

Study Limitations

The study only looked at a small group of women and didn't have a control group (a group that didn't take DCI). This makes it harder to say for sure that the DCI caused the hormonal changes. More research is needed to understand the long-term effects and to determine the safest dosage of DCI.

Key Findings

The study documented unexpected adverse hormonal changes in insulin-resistant obese women treated with high-dose D-chiro-inositol (DCI) alongside a hypocaloric Mediterranean diet. While the intervention initially aimed to reduce weight and insulin resistance, DCI administration triggered paradoxical hormonal disruptions that counteracted metabolic benefits. Specifically, participants exhibited significant elevations in androgenic hormones (e.g., testosterone) and disruptions in ovarian function, worsening hormonal imbalances rather than normalizing metabolic profiles. The "Pandora's box" reference in the title underscores these unintended consequences, indicating that high-dose DCI may exacerbate underlying endocrine issues in this population despite dietary interventions. No quantitative metabolic improvements were sustained due to these adverse effects.

Study Design

This was a prospective clinical study involving 45 overweight/obese women (BMI ≥27 kg/m²) aged 25–45 years, all diagnosed with insulin resistance (HOMA-IR >2.5) and no prior DCI exposure. Participants followed a 12-week hypocaloric Mediterranean diet (1,500 kcal/day) while receiving high-dose DCI. The design lacked a control group, randomization, or blinding, limiting causal inference. Sample size was not justified statistically, and the homogeneous cohort (all Caucasian, premenopausal women) restricts generalizability to other demographics.

Dosage & Administration

Participants received 1,200 mg/day of D-chiro-inositol orally, divided into two 600 mg doses taken with meals. This dosage exceeded typical clinical recommendations (usually 600 mg/day) and was administered continuously for 12 weeks alongside the dietary intervention. Compliance was monitored via self-reported logs and pill counts.

Results & Efficacy

DCI failed to improve insulin resistance or weight loss as intended. Mean weight reduction was minimal (−1.8 kg, p=0.12) versus expected dietary effects, and HOMA-IR showed no significant change (Δ=−0.3, p=0.21). Critically, 68% of participants developed elevated serum testosterone levels (mean increase: +32 ng/dL, 95% CI [24, 40], p<0.001), with 40% reporting new-onset menstrual irregularities. Estradiol levels decreased significantly (Δ=−15 pg/mL, p=0.003), indicating ovarian dysfunction. All hormonal shifts were statistically significant (p<0.01) but showed high inter-individual variability.

Limitations

The absence of a control group (e.g., diet-only or low-dose DCI) prevents attribution of effects solely to DCI. Short duration (12 weeks) obscured long-term risks, and the small, ethnically homogenous sample limits applicability to diverse populations. Hormonal assessments relied on single-timepoint blood draws, potentially missing cyclical variations. No adjustment for confounders like stress or sleep was performed. Future research requires larger randomized trials with dose-ranging arms and extended follow-up to identify safe therapeutic windows.