Effect of curcumin plus piperine co-supplementation on glycemic control in adults: A meta-analysis of randomized...

Poor glycemic control leading to hyperglycemia is a major risk factor for diabetes and its complications. Several primary studies have demonstrated that co-supplementation with curcumin plus piperine (Curc + Pipe) can enhance glycemic control. However, findings across studies are inconsistent. This meta-analysis aims to evaluate the efficacy of Curc + Pipe in glycemic indices in adults.

A comprehensive search of major databases was conducted through October 2025 to identify eligible randomized controlled trials (RCTs). Extracted data included fasting blood glucose (FBG), hemoglobin A1c (HbA1c), fasting insulin (FI), and the homeostatic model assessment for insulin resistance (HOMA-IR). Outcomes were pooled using a random-effects model, with weighted mean differences (WMDs) and 95% confidence intervals (CIs).

This meta-analysis included 15 RCTs comprising 1,020 participants (514 in the intervention group and 506 in the control group). Pooled analyses demonstrated that Curc + Pipe co-supplementation significantly reduced FBG (WMD: -5.89 mg/dL; 95% CI: [- 9.52, - 2.26], p = 0.001). However, no significant effects were observed for HbA1c (WMD: -0.34%; 95% CI: [- 0.80, 0.11], p = 0.135), FI (WMD: -0.19 mIU/L; 95% CI: [- 1.44, 1.83], p = 0.815), or HOMA-IR (WMD: -0.02; 95% CI: [- 0.67, 0.63], p = 0.957). According to the GRADE assessment, the certainty of evidence was rated as low for FBG, HbA1c, and FI, and moderate for HOMA-IR, indicating limited confidence in the overall findings.

Curc + Pipe co-supplementation may modestly improve FBG in adults, particularly in overweight patients with metabolic disorders, but the low-quality evidence, small effect sizes, and non-significant effects on HbA1c, FI, and HOMA-IR limit its clinical relevance. Well-designed, large-scale RCTs are needed to confirm these findings, clarify mechanisms, and determine their potential role in metabolic health management.

The online version contains supplementary material available at 10.1007/s40200-025-01799-y.