What the reviews found
Supplements for Blood Sugar
24 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.
- 3 reviews citedTop-scored productBulkSupplements Gymnema Extract Powder90Benefithba1c
“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
- 2 reviews citedTop-scored productPure Encapsulations Astaxanthin93Benefitfasting 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
- 2 reviews citedTop-scored productThorne Super EPA92Benefitfasting 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
- 3 reviews citedTop-scored productThorne Berberine96Benefitglycemic 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
- 2 reviews citedTop-scored productNOW Foods Certified Organic Chlorella87Benefitfasting 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
- 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
- 1 review citedTop-scored productBulkSupplements Artichoke Extract Capsules92Benefitglycemic indices
“The supplementation of artichoke and artichoke products can significantly reduce the FBS concentrations in humans.” PMID 32951745
- 1 review citedTop-scored productNutricost Beta Alanine Powder96Benefitglycemic control
“Carnosine and β-alanine supplementation show potential as adjunct therapies for improving FBG, HbA1c and HOMA-β in prediabetes and T2DM.” PMID 40999397
- 1 review citedTop-scored productPure Encapsulations Bromelain 240086Benefitglycemic and lipid indices
“Bromelain supplementation is effective in improving glycemic and lipid indices in diabetes.” PMID 40440445
- 1 review citedTop-scored productThorne Chromium Picolinate92Benefitglycemic 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 citedTop-scored productMegaFood Baby & Me 2 Prenatal Probiotic + Prebiotic88Benefitinsulin 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
- 1 review citedTop-scored productNutricost L-Isoleucine Capsules92Benefitpostprandial glucose response
“attenuated the glucose response compared to glucose intake alone in healthy participants” PMID 33096658
- 1 review citedTop-scored productBluebonnet Nutrition ADVANCED PROBIOTICS CHEWABLE ACIDOPHILUS64Benefitinsulin 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
- 1 review citedTop-scored productThorne Magnesium Glycinate96Benefitinsulin 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
- 1 review citedTop-scored productNootropics Depot Taurine Capsules93Benefitglycemic control
“Long-term taurine supplementation is particularly effective in improving glycemic control and insulin sensitivity in obesity.” PMID 39796489
- 1 review citedTop-scored productThorne Zinc Bisglycinate 30 mg96Benefitinsulin 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.
- 2 reviews citedTop-scored productJarrow Formulas MK-7 - 90mcg95Benefitinsulin 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.
- 3 reviews citedTop-scored productPure Encapsulations Melatonin 3 mg92No 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
- 2 reviews citedTop-scored productPure Encapsulations Curcumin90Benefitfasting 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
- 2 reviews citedTop-scored productThorne Selenium96Benefithoma-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
- 1 review citedTop-scored productNootropics Depot Acetyl L-Carnitine HCL (ALCAR) Capsules94Benefitfasting 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.
- 1 review citedTop-scored productNOW Foods Alpha Lipoic Acid88No 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
- 1 review citedTop-scored productNutricost TMG Capsules92No 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
- 1 review citedTop-scored productNutricost Cayenne Pepper Capsules86No 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
- 1 review citedTop-scored productPure Encapsulations DL-Phenylalanine90No 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
- 2 reviews citedTop-scored productProHealth Longevity NMN Pro 1000™86No 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
- 1 review citedTop-scored productGarden of Life Dr. Formulated Probiotics Kids - Strawberry82No 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
- 3 reviews citedTop-scored productPure Encapsulations Resveratrol90No 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
- 1 review citedTop-scored productNutricost Vitamin E Softgels88No 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, Inositol, Isoflavones, Lysine, Milk Thistle, Moringa, Piperine, Pomegranate, Steviol Glycosides, Vanadium, Watermelon could not conclude either way on blood sugar.
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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). The full report explains how the conclusions were read and checked.
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.