What the reviews found
Supplements for Blood Sugar
25 where systematic reviews concluded a benefit, 7 with mixed findings, 13 where they concluded no effect. Every line quotes the review and links it, so you can read the sentence yourself.
Reviews found a benefit
Systematic reviews concluded these improve an outcome tied to blood sugar, and none concluded no effect.
- Benefithba1c
“glycated haemoglobin (HbA1c) (SMD 3.91, 95% CI 7.35 to -0.16%, p < .0001, I2 99%) compared to baseline.” PMID 34467577
Benefitpostprandial blood glucose“postprandial blood glucose (PPBG) (SMD 1.04 mg/dl, 95% CI 1.53 to -0.54, p < .0001, I2 80%)” PMID 34467577
Benefitglucose absorption“also inhibits glucose absorption.” PMID 24166097
- Cinnamon4 reviews citedBenefitglycemic control
“Our analysis indicated that glycemic control indicators are significantly decreased by cinnamon supplementation.” PMID 37818728 · 4 reviews
Benefitblood glucose control(as Cinnamomum verum)“Cinnamon supplementation likely has a modest positive effect on BG.” PMID 38466959
- Benefitfasting insulin
“fasting blood insulin (astaxanthin: -2.66 [-3.98, -1.34] pmol/L).” PMID 39064656
Benefitinsulin sensitivity“Combined ASX and exercise interventions improved body composition, lipid profiles, insulin sensitivity, and immune recovery.” PMID 41596351
- 2 reviews citedBenefitblood glucose(as Beta Hydroxybutyrate)
“exogenous ketones increased blood BHB (MD = 1.73 mM; 95% CI: 1.26, 2.21 mM; P < 0.001) and decreased mean blood glucose (MD = -0.54 mM; 95% CI: -0.68, -0.40 mM; P < 0.001)” PMID 35380602
Benefitblood glucose“Following ingestion, exogenous ketones increased blood BHB (MD = 1.73 mM; 95% CI: 1.26, 2.21 mM; P < 0.001) and decreased mean blood glucose (MD = -0.54 mM; 95% CI: -0.68, -0.40 mM; P < 0.001).” PMID 35380602 · 2 reviews
- Bilberry2 reviews citedBenefithba1c(as Vaccinium myrtillus)
“Bilberry and blackcurrant extract lowered average levels of glycated hemoglobin (HbA1c), at least in Chinese subjects, especially in those who were older, who were diagnosed with Type 2 Diabetes Mellitus (T2DM) and who were participating in longer-term studies.” PMID 34067538
Benefithba1c“Bilberry and blackcurrant extract lowered average levels of glycated hemoglobin (HbA1c), at least in Chinese subjects” PMID 34067538 · 2 reviews
- Benefitfasting blood glucose(as Omega-3)
“there was a significant effect on the reduction of fasting blood glucose [SMD: -0.48; CI95%: -0.76, -0.19; p = 0.01; I2 = 88%]” PMID 33480268
Benefitinsulin resistance(as Omega-3)“insulin resistance [SMD: -0.61; CI95%: -0.98, -0.24; p = 0.01; I2 = 90%]” PMID 33480268
- Top-scored productThorne Berberine3 reviews cited96Benefitglycemic control
“BBR supplementation was effective in reducing fasting blood glucose (FBG) (ESWMD: -0.77; 95% CI: -0.90 to -0.63, and ESSMD: -0.65; 95% CI: -0.83 to -0.47), hemoglobin A1C (HbA1C) (ESWMD: -0.57; 95% CI: -0.68 to -0.46), homeostasis model assessment for insulin resistance (HOMA-IR) (ESWMD: -1.04; 95% CI: -1.66 to -0.42, and ESSMD: -0.71; 95% CI: -0.97 to -0.46), insulin (ESWMD: -1.00; 95% CI: -1.70 to -0.30, and ESSMD: -0.63; 95% CI: -0.94 to -0.32), interleukin (IL)-6 (ESSMD: -1.23; 95% CI: -1.61 to -0.85), tumor necrosis factor-α (TNF-α) (ESSMD: -1.04; 95% CI: -1.28 to -0.79), and C-reactive protein (CRP) (ESWMD: -0.62; 95% CI: -0.74 to -0.50, and ESSMD: -1.70; 95% CI: -2.21 to -1.19).” PMID 38016844 · 3 reviews
- Top-scored productNutricost Chlorella Capsules2 reviews cited80Benefitfasting blood glucose
“fasting blood sugar (FBS) (WMD= -6.25, 95% CI: -9.02, -3.47)” PMID 41652544 · 2 reviews
- Chlorogenic Acid2 reviews citedBenefitfasting blood glucose
“Decaffeinated coffee (510.6 mg) reduced fasting blood glucose levels (WMD = -0.81; 95% CI: -1.65, 0.03).” PMID 34577880 · 2 reviews
- Benefitinsulin treatment need and homa-ir(as Myo-Inositol)
“Myo-inositol supplementation is effective to decrease the need of insulin treatment and HOMA-IR for gestational diabetes.” PMID 39115013
- 2 reviews citedBenefitblood glucose levels
“Oral AA ingestion as well as intravenous AA infusion was able to stimulate an insulin response and decrease glucose concentrations in T2DM and obese individuals.” PMID 33096658
- Anthocyanins1 review citedBenefitblood glucose control
“modest reductions in HbA1c (~0.3-0.5%)” PMID 42280140
- Benefitglycemic indices
“The supplementation of artichoke and artichoke products can significantly reduce the FBS concentrations in humans.” PMID 32951745
- Benefitglycemic control
“Carnosine and β-alanine supplementation show potential as adjunct therapies for improving FBG, HbA1c and HOMA-β in prediabetes and T2DM.” PMID 40999397
- Benefitglycemic and lipid indices
“Bromelain supplementation is effective in improving glycemic and lipid indices in diabetes.” PMID 40440445
- Top-scored productThorne Chromium Picolinate1 review cited92Benefitglycemic control
“Glycemic control markers, including FPG, insulin, HbA1C, and HOMA-IR levels, significantly decrease following chromium supplementation, mainly in studies with a longer intervention period.” PMID 39541030
- Hydroxytyrosol1 review citedBenefitglucose metabolism
“Flavonoid-enriched chocolate, hydroxytyrosol-fortified bread, and other products influenced glucose metabolism.” PMID 38214689
- 1 review citedBenefitinsulin sensitivity
“Beneficial health effects reported following ITF intake include improved intestinal barrier function, improved laxation, increased insulin sensitivity, decreased triglycerides and an improved lipid profile, increased absorption of calcium and magnesium, and increased satiety.” PMID 34555168
- Benefitpostprandial glucose response
“attenuated the glucose response compared to glucose intake alone in healthy participants” PMID 33096658
- 1 review citedBenefitinsulin resistance
“Probiotics supplementation significantly reduced insulin resistance (MD: -1.05 HOMA-IR score, p < 0.00001)” PMID 40550754
- 1 review citedBenefitfasting glucose and hba1c
“L. plantarum supplementation reduced the levels of fasting plasma glucose (-0.41, 95%CI -0.63, -0.19 mg/dL; n = 5) and hemoglobin A1c (-0.2, 95%CI: -0.3, 0%; n = 4).” PMID 38777458
- Top-scored productThorne Magnesium Glycinate1 review cited96Benefitinsulin resistance
“Mineral supplementation may improve insulin resistance and selected metabolic parameters in PCOS, with the most consistent effects observed for glycemic indices.” PMID 41580698
- 1 review citedBenefithba1c
“Rice bran significantly reduced systolic blood pressure (WMD: -3.336 mmHg; p = 0.0006), diastolic blood pressure (WMD: -3.145 mmHg; p = 0.015), and HbA1c (WMD: -0.199%; p = 0.003).” PMID 41009614
- Benefitglycemic control
“Long-term taurine supplementation is particularly effective in improving glycemic control and insulin sensitivity in obesity.” PMID 39796489
- Top-scored productThorne Zinc Bisglycinate 30 mg1 review cited96Benefitinsulin resistance
“Zinc supplementation was associated with improvements in insulin resistance, inflammatory status and oxidative stress markers in individuals with diabetes.” PMID 42594341
Mixed: a benefit on one measure, no effect on another
- Vitamin K12 reviews citedBenefitfasting blood glucose
“The evidence showed a significant reduction in FBG, SMD = -0.22 (-0.39 to -0.05),” PMID 41599883
Benefithba1c“HbA1c, MD = -1.00%, 95% CI (-1.92 to -0.07)” PMID 41599883
Benefithoma-ir“vitamin K supplementation can reduce homeostatic model assessment insulin resistance (HOMA-IR) (WMD: -0⋅24, 95 % CI: -0⋅49, -0⋅02, P = 0⋅047) significantly compared to the placebo group.” PMID 38282652 · 2 reviews
1 more review finding.
- Top-scored productJarrow Formulas MK-7 - 90mcg2 reviews cited95Benefitinsulin resistance (homa-ir)
“vitamin K supplementation can reduce homeostatic model assessment insulin resistance (HOMA-IR) (WMD: -0⋅24, 95 % CI: -0⋅49, -0⋅02, P = 0⋅047) significantly compared to the placebo group.” PMID 38282652 · 2 reviews
Benefitfasting blood glucose“significant reduction in FBG, SMD = -0.22 (-0.39 to -0.05)” PMID 41599883
Benefithba1c“HbA1c, MD = -1.00%, 95% CI (-1.92 to -0.07)” PMID 41599883
1 more review finding — see Vitamin K2.
- No effectfasting glucose
“The meta-analysis showed no significant reduction in fasting glucose levels.” PMID 42070664
Benefitperiodontal and glycemic outcomes“Antioxidants, particularly melatonin and propolis, enhance periodontal and glycemic outcomes in T2D-periodontitis patients.” PMID 41158097
- Top-scored productPure Encapsulations Curcumin2 reviews cited90Benefitfasting glucose
“Curcumin supplementation was associated with decreases in body weight (up to 0.82 kg), BMI (up to 0.30 kg/m2), triglycerides, total cholesterol, and fasting glucose levels.” PMID 42280140
No effectglycemic control“Current evidence suggests that short-term nanocurcumin supplementation does not significantly improve glycemic control, lipid profile or systemic inflammation in patients with T2DM.” PMID 42171191
- Lignans2 reviews citedBenefithba1c
“ficantly reduced hemoglobin A1c (HbA1c) in participants with T2DM compared with the control group.” PMID 36640581
No effectfasting blood glucose“it had no effects on body weight, body mass index, blood pressure, fasting blood glucose (FBG), homeostatic model assessment for insulin resistance, quantitative insulin sensitivity check index, and lipid parameters.” PMID 36640581
- Top-scored productThorne Selenium2 reviews cited96Benefithoma-β (beta-cell function)
“dietary selenium significantly reduced HOMA-β (Homeostasis Model Assessment-Beta; p < 0.0001)” PMID 41738711
No effectinsulin resistance (homa-ir)“selenium had no significant effect on fasting plasma glucose, insulin levels, HOMA-IR (Homeostasis Model Assessment of Insulin Resistance), total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, nitric oxide, plasma glutathione, weight change, and body mass index change (all p > 0.05)” PMID 41738711
- Benefitfasting blood glucose
“Carnitine supplementation significantly reduced fasting blood sugar (FBS; WMD -2.93 mg/dL, 95 % CI -5.20 to -0.65), fasting insulin (WMD -3.54 μU/mL, 95 % CI -7.00 to -0.07), and HOMA-IR (WMD -0.69, 95 % CI -1.26 to -0.13), but had no significant effect on QUICKI.” PMID 41177307
No effectinsulin sensitivity (quicki)“Carnitine supplementation significantly reduced fasting blood sugar (FBS; WMD -2.93 mg/dL, 95 % CI -5.20 to -0.65), fasting insulin (WMD -3.54 μU/mL, 95 % CI -7.00 to -0.07), and HOMA-IR (WMD -0.69, 95 % CI -1.26 to -0.13), but had no significant effect on QUICKI.” PMID 41177307
Reviews found no effect
Reviews studied these for an outcome tied to blood sugar and concluded they made no difference.
- No effectnafld markers (liver enzymes, lipids, glycemic indices, obesity)
“ALA supplementation did not improve liver enzymes, lipid profiles, glycemic indices, adipocytokines, and obesity measures in patients with NAFLD.” PMID 41917882
- Top-scored productNutricost TMG Capsules1 review cited92No effectfasting blood glucose
“Moreover, our analysis indicated that betaine supplementation did not affect serum concentrations of triglyceride (TG), high-density lipoprotein (HDL), fasting blood glucose (FBG), C-reactive protein (CRP), liver enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT)], and blood pressure.” PMID 33764214
- No effectglycemic control
“Overall, these data suggest that capsinoids and red pepper supplementation did not have beneficial effects on glucose, insulin, HbA1C and HOMA-IR but significantly reduce glucose in people older than 40 years.” PMID 34487384
- Catechins1 review citedNo effectfasting insulin
“the effect on fasting insulin was not statistically significant (WMD: -0.50; 95% CI: -1.46, 0.47; P = 0.313), indicating a lack of robust or consistent impact on this parameter across studies.” PMID 40885603
- No effectblood glucose concentration
“Oral ingestion of most individual AAs induced an insulin response, but did not alter glucose concentrations in healthy participants.” PMID 33096658
- Melissa officinalis1 review citedNo effecthba1c
“MO intake was not associated with statistically significant changes in triglycerides, low-density lipoprotein, diastolic blood pressure, high sensitivity c-reactive protein levels, fasting blood sugar, HbA1c, insulin or high-density lipoprotein levels.” PMID 32614129
- No effectglucose and lipid metabolism markers
“The random-effects meta-analyses indicated no significant benefit of NMN on fasting glucose, fasting insulin, glycated hemoglobin, homeostatic model assessment for insulin resistance and lipid profile.” PMID 39531138
- Oleuropein1 review citedNo effectglycemic outcomes
“pooled analyses demonstrated no statistically or clinically significant effects on glycemic or lipid outcomes” PMID 41848522
- Olive Oil1 review citedNo effectglycemic and lipid markers
“pooled analyses demonstrated no statistically or clinically significant effects on glycemic or lipid outcomes” PMID 41848522
- No effectbmi z-score, waist circumference, body fat percentage, and glucose metabolism
“Current evidence does not support clear benefits for BMI z-score, waist circumference, body fat percentage, or glucose metabolism.” PMID 42588161
- No effectglycemic indices and lipid profile in type 2 diabetes
“resveratrol supplementation was not considered as a beneficial agent in declining glycemic indices and lipid profile in patients with T2DM.” PMID 42268476
- 1 review citedNo effectanthropometric and glycemic indices
“Tart cherry supplementation did not have significant effects on anthropometric and glycemic indices, but can improve lipid profile, especially in a single dose, longer duration, and in elderly, obese, and unhealthy individuals.” PMID 38759306
- No effectglycemic control
“However, their effects on glycemic control, diastolic blood pressure, and blood lipids other than HDL were comparable.” PMID 41521729
Not enough to say
Reviews of Aloe Vera, Blueberry, Chicory, CoQ10, Ginger, Green Tea, Isoflavones, Lysine, Milk Thistle, Moringa, Piperine, Pomegranate, Steviol Glycosides, Vanadium, Watermelon could not conclude either way on blood sugar.
How this page is built
Each finding is the conclusion a set of systematic reviews reached on one outcome — whether an ingredient helped, made no difference, or could not be judged — with a sentence quoted from one review, checked to appear in its PubMed abstract. It records the direction, not the size, of an effect. Reviews run in populations such as people with cancer, pregnancy, surgery or children are left out, because applying them to a general reader would mislead. Evidence last refreshed September 2026. Abstracts courtesy of the U.S. National Library of Medicine (PubMed).
Other goals
Educational only. A review finding a benefit on average does not mean a supplement will help you, or that it is safe alongside your medication. If you are treated for blood sugar, talk to your clinician before adding anything.