Effectiveness of Combining Gegen Qinlian Decoction with Metformin in Managing Type 2 Diabetes Mellitus

Overview

This systematic review and meta-analysis evaluated the efficacy of Gegen Qinlian Decoction (GQD) combined with metformin in adults with type 2 diabetes mellitus (T2DM). The findings indicate reductions in fasting plasma glucose and 2-hour postprandial glucose were observed, albeit with very low certainty of evidence.

Background

Type 2 diabetes mellitus (T2DM) is a prevalent chronic condition characterized by hyperglycemia due to insulin resistance. Metformin is the first-line treatment for T2DM, but some patients may require additional therapies for optimal glycemic control. GQD is a traditional Chinese medicine often used alongside metformin, yet the clinical evidence supporting its efficacy remains unclear due to variability in study design and outcomes.

Data Highlights

Key Findings

• Eight randomized controlled trials with 725 participants were included in the analysis.
• No statistically significant reduction in HbA1c was observed with GQD plus metformin compared to metformin alone.
• Significant reductions in fasting plasma glucose and 2-hour postprandial glucose were noted.
• Substantial heterogeneity was present across analyses (I² = 85%–100%).
• The certainty of evidence was rated as very low due to risk of bias and imprecision.
• Post-treatment sensitivity analyses showed reductions in all glycemic outcomes but were also affected by high risk of bias.

Clinical Implications

Clinicians should consider the very low certainty of evidence when evaluating adjunctive therapies for T2DM.

Conclusion

Further research with larger, well-designed trials is necessary to clarify the role of GQD in treatment.

Related Resources & Content

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2. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes—2026 | Diabetes Care | American Diabetes Association
3. Guidelines on primary healthcare for type 2 diabetes in China, 2025 - PMC
4. JAMA Network Open — HRS-7535 for Type 2 Diabetes Inadequately Controlled With Metformin: A Randomized Clinical Trial
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8. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes—2026 | Diabetes Care | American Diabetes Association
9. Guidelines on primary healthcare for type 2 diabetes in China, 2025 - PMC
10. Frontiers | Efficacy of Gegen Qinlian decoction plus metformin for type 2 diabetes mellitus: a systematic review and meta-analysis of randomized controlled trials
11. Gegen Qinlian decoction ameliorates insulin resistance in type 2 diabetes: A systematic review and meta-analysis of RCTs with mechanistic insights into SIRT1/AMPK pathway activation - ScienceDirect