Turmeric and Reduced Hemoglobin A1c

Research synthesisLow evidenceMixed effect size4 studies · 3 beneficial · 1 neutral · 0 harmful

Across 4 studies, 3 reported beneficial effects (small to moderate) of turmeric/curcumin on reducing Hemoglobin A1c, and 1 study was neutral. The median study duration was 365 days, based on a single high-quality 12-month RCT using 1500 mg/day in adults with type 2 diabetes. Effect sizes were mixed (small to moderate) across studies.

Effective dose range: 1500 mg/day
Studied populations: adults with type 2 diabetes mellitus

Caveats: Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Many studies did not report dose, form, or duration, limiting confidence in the findings. The evidence base is small (only 4 studies) — conclusions should be considered preliminary.

Generated Jun 13, 2026

Doses used in studies

mg/day: 1,500 (median 1,500, IQR 1,500–1,500) — 1 study

Time to effect

Median: 12.2 months · IQR 12.2 months–12.2 months · Range 12.2 months–12.2 months — Reported in 1 of 4 studies

Safety in these studies

blood pressureNo significant difference
No significant effects were observed on total cholesterol, blood pressure, body mass index, blood urea nitrogen, or creatinine levels.
from: Antidiabetic and Metabolic Effects of Turmeric (Curcuma Longa) in Patients with Type 2 Dia
blood urea nitrogenNo significant difference
No significant effects were observed on total cholesterol, blood pressure, body mass index, blood urea nitrogen, or creatinine levels.
from: Antidiabetic and Metabolic Effects of Turmeric (Curcuma Longa) in Patients with Type 2 Dia
body mass indexNo significant difference
No significant effects were observed on total cholesterol, blood pressure, body mass index, blood urea nitrogen, or creatinine levels.
from: Antidiabetic and Metabolic Effects of Turmeric (Curcuma Longa) in Patients with Type 2 Dia
creatinineNo significant difference
No significant effects were observed on total cholesterol, blood pressure, body mass index, blood urea nitrogen, or creatinine levels.
from: Antidiabetic and Metabolic Effects of Turmeric (Curcuma Longa) in Patients with Type 2 Dia
Overall tolerabilityReported
No significant effects were observed on total cholesterol, blood pressure, body mass index, blood urea nitrogen, or creatinine levels.
from: Antidiabetic and Metabolic Effects of Turmeric (Curcuma Longa) in Patients with Type 2 Dia
Overall tolerabilityReported
No explicit adverse events or safety findings are reported in the abstract.
from: Clinical Potential of Curcuma longa Linn. as Nutraceutical/Dietary Supplement for Metaboli

4 of 4 papers

Curcumin Supplementation Reduces Inflammation, Neutrophil-to-Lymphocyte Ratio (NLR), and Antioxidant Status in Obese Patients with Type 2 Diabetes: A Randomized Controlled Trial.
- 2026-04-27
- RCT · n = 114
- International journal of molecular sciences 27(9)
- - Metha Yaikwawong
  - Khanittha Kamdee
  - Somlak Chuengsamarn
- PubMed: 42123439
- DOI: 10.3390/ijms27093854
8 Insights on
- Reduced Hemoglobin A1c
- High evidence
- Large Human Trial
- Rigorous Journal
- Clinical
HbA1c (6.10% vs. 6.40%; p < 0.05)
Effect
Beneficial
Effect size
Small
Significant
Yes
Dose
1500 mg/day
Comparative effectiveness of six herbs in the management of glycemic status of type 2 diabetes mellitus patients: A systematic review and network meta-analysis of randomized controlled trials.
- 2023-08
- Systematic Review · n = 3,130
- Diabetes & metabolic syndrome 17(8)
- - Subodh Kumar
  - Suresh K Sharma
  - Shiv Kumar Mudgal
  - Rakhi Gaur
  - Rajat Agarwal
  - Harminder Singh
  - Sanjay Kalra
- PubMed: 37451111
- DOI: 10.1016/j.dsx.2023.102826
2 Insights on
- Reduced Hemoglobin A1c
- High evidence
- Clinical
only ACV (SMD = -2.10) and fenugreek seeds (0.84) were found significantly effective in reducing HbA1C.
Effect
Neutral
Effect size
Small
Significant
No
Antidiabetic and Metabolic Effects of Turmeric (Curcuma Longa) in Patients with Type 2 Diabetes Mellitus or Hyperglycemia - A Systematic Meta-Review and Meta-Analysis.
- 2025-10-17
- Meta-Analysis
- Journal of Nepal Health Research Council 23(02)
- - Kapil Amgain
  - Richa Shah
  - Siti Munirah Md Noh
  - Shamsher Shrestha
  - Bijay Aryal
  - Lok Raj Joshi
  - Sujana Neupane
  - Shamima Abdul Rahman
- PubMed: 41319069
- DOI: 10.33314/jnhrc.v23i02.4708
10 Insights on
- Reduced Hemoglobin A1c
- High evidence
- Clinical
The pooled analysis revealed that curcumin significantly reduced ... HbA1c (MD = - 0.31%; 95% CI: - 0.57, - 0.05)
Effect
Beneficial
Effect size
Moderate
Significant
Yes
Clinical Potential of Curcuma longa Linn. as Nutraceutical/Dietary Supplement for Metabolic Syndrome: Systematic Review and Meta-Analysis of Randomized Controlled Trials.
- 2025-12-24
- Review
- Foods (Basel, Switzerland) 15(1)
- - Samuel Abiodun Kehinde
  - Zahid Naeem Qaisrani
  - Rinrada Pattanayaiying
  - Bo Bo Lay
  - Khin Yadanar Phyo
  - Wai Phyo Lin
  - Myat Mon San
  - Nurulhusna Awaeloh
  - Sasithon Aunsorn
  - Ran Kitkangplu
  - Sasitorn Chusri
- PubMed: 41517125
- DOI: 10.3390/foods15010060
9 Insights on
- Reduced Hemoglobin A1c
- Low evidence
- Clinical
HbA1c (SMD = -0.41, 95% CI -0.60 to -0.23) in T2DM
Effect
Beneficial
Effect size
Moderate
Significant
Yes

Turmeric and Reduced Hemoglobin A1c

Curcumin Supplementation Reduces Inflammation, Neutrophil-to-Lymphocyte Ratio (NLR), and Antioxidant Status in Obese Patients with Type 2 Diabetes: A Randomized Controlled Trial.

Comparative effectiveness of six herbs in the management of glycemic status of type 2 diabetes mellitus patients: A systematic review and network meta-analysis of randomized controlled trials.

Antidiabetic and Metabolic Effects of Turmeric (Curcuma Longa) in Patients with Type 2 Diabetes Mellitus or Hyperglycemia - A Systematic Meta-Review and Meta-Analysis.

Clinical Potential of Curcuma longa Linn. as Nutraceutical/Dietary Supplement for Metabolic Syndrome: Systematic Review and Meta-Analysis of Randomized Controlled Trials.