Metabolic Health

High blood sugar

About High blood sugar — Metabolic Health.

Type 2 diabetes, prediabetes, insulin resistance and metabolic syndrome — where the aim is lower blood sugar.

27studies analysed

7compounds with evidence

Systematic reviewstrongest evidence

Where research is strongest

Add your outcome — free & pseudonymous

Tried something for High blood sugar? Share how it went — only ever published as part of a group of 10+.

9linked compounds

22linked studies

0published community reports

Results By the numbers Community Research Compounds

Headline results for High blood sugar.

Figures as the studies reported them.

Colour keyReported a benefitNo clear benefitUnclearPossible harmAmber is for highlights, such as where the most research is. It never means a result was good.

Fenugreek

17 of 20 results reported a benefit

6 studies, including a review of trials

Long-term blood sugar (HbA1c)0.99 %lowerAverage of 2 results (from 0.85 % lower to 1.13 % lower) · 2 reviews of trials4 of 4 results reported a benefit2014 study 1 ↗2011 study 2 ↗
Fasting blood sugar0.96 mmol/llower1 review of trials3 of 3 results reported a benefit2014 study ↗
Blood sugar after glucose drink2.19 mmol/llower1 review of trials2 of 2 results reported a benefit2014 study ↗

No figure given: Blood sugar control (general) (reported a benefit).

Also measured alongside: Triglycerides (blood fats) (reported a benefit); 'Bad' (LDL) cholesterol (mixed results); 'Good' (HDL) cholesterol (reported a benefit); and 3 more.

Every result

Spirulina

31 of 35 results reported a benefit

5 studies, including a review of trials

Fasting blood sugar5.51 mg/dllower1 review of trials4 of 4 results reported a benefit2025 study ↗
Long-term blood sugar (HbA1c)No clear difference0.59 higher, unit not reported1 review of trials1 of 2 results reported a benefit2022 study ↗

Also measured alongside: Triglycerides (blood fats) (reported a benefit); Diastolic blood pressure (reported a benefit); Systolic blood pressure (reported a benefit); and 12 more.

Every result

Psyllium

9 of 15 results reported a benefit

3 studies, including a review of trials

Fasting blood sugar6.89lower, unit not reported1 review of trials3 of 3 results reported a benefit2024 study ↗
Long-term blood sugar (HbA1c)0.75lower, unit not reported1 review of trials3 of 3 results reported a benefit2024 study ↗

No figure given: Blood sugar levels (unspecified) (no clear benefit).

Also measured alongside: Triglycerides (blood fats) (reported a benefit); 'Bad' (LDL) cholesterol (reported a benefit); 'Good' (HDL) cholesterol (no clear benefit); and 5 more.

Every result

Resveratrol

2 of 13 results reported a benefit

3 studies, including a review of trials

Long-term blood sugar (HbA1c)No clear difference0.1 % higher1 review of trials1 of 3 results reported a benefit2020 study ↗
Fasting blood sugarNo clear difference2 mg/dL higher1 review of trials0 of 2 results reported a benefit2020 study ↗

No figure given: Blood sugar control (general) (unclear).

Also measured alongside: Triglycerides (blood fats) (no clear benefit); 'Bad' (LDL) cholesterol (reported a benefit); 'Good' (HDL) cholesterol (no clear benefit); and 3 more.

Every result

NMN

3 of 21 results reported a benefit

4 studies, including a review of trials

Fasting blood sugarNo clear benefit foundNMN supplementation did not significantly improve fasting glucose with no comparator reported; the difference versus the comparator was not statistically established in 513.2 reviews of trials · no comparable figure reported0 of 2 results reported a benefit2025 study ↗

No figure given: Long-term blood sugar (HbA1c) (no clear benefit).

Also measured alongside: Blood fats (general) (no clear benefit); Triglycerides (blood fats) (no clear benefit); 'Bad' (LDL) cholesterol (no clear benefit); and 14 more.

Every result

Berberine

13 of 13 results reported a benefit

3 studies, including a review of trials

Blood sugar after meals0.94 mmol/Llower1 review of trials2019 study ↗
Fasting blood sugar0.54 mmol/Llower1 review of trials2019 study ↗
Blood sugar after glucose drinkFell from 10.44 to 8.12 mmol/L1 randomised trial2023 study ↗

No figure given: Blood sugar levels (unspecified) (reported a benefit).

Also measured alongside: Blood fats (general) (reported a benefit); Body measurements and composition (reported a benefit); Bowel polyps (adenomas) (reported a benefit); and 4 more.

1 more measure

Glycine

7 of 8 results reported a benefit

3 randomised trials, 12 people

Blood sugar after glucose drinkReported a benefitsee exact figuresGlycine improved Plasma glucose area response (> 50%) compared with glucose alone in Nine (2-h).1 randomised trial2002 study ↗

No figure given: Long-term blood sugar (HbA1c) (reported a benefit).

Also measured alongside: Interferon-gamma (immune signal) (reported a benefit); Insulin response to glucose (reported a benefit); Insulin sensitivity (glucose disposal) (no clear benefit); and 1 more.

Every result

Where the evidence is concentrated.

Published research

High blood sugar: findings by compound

What this means: Bars count reported findings, not treatment effectiveness or certainty.

One study may report several findings or appear in more than one pairing. Counts do not show the size of an effect. Comparable numerical estimates are not established for this summary.

View the full data table

Published research: reported directions by pairing
Compound and condition	Findings (count)	Studies (count)	Reported results (finding counts)	How sure?
Fenugreek	20	6	Benefit: 17; no benefit: 3; harm: 0; unclear: 0; not recorded / unrecognised: 0	Not formally graded
Spirulina	35	5	Benefit: 31; no benefit: 4; harm: 0; unclear: 0; not recorded / unrecognised: 0	Not formally graded
Psyllium	15	3	Benefit: 9; no benefit: 6; harm: 0; unclear: 0; not recorded / unrecognised: 0	Not formally graded
Resveratrol	14	3	Benefit: 2; no benefit: 10; harm: 0; unclear: 2; not recorded / unrecognised: 0	Not formally graded
NMN	21	4	Benefit: 3; no benefit: 18; harm: 0; unclear: 0; not recorded / unrecognised: 0	Not formally graded
Berberine	14	3	Benefit: 13; no benefit: 0; harm: 1; unclear: 0; not recorded / unrecognised: 0	Not formally graded
Glycine	8	3	Benefit: 7; no benefit: 1; harm: 0; unclear: 0; not recorded / unrecognised: 0	Not formally graded

Degree of benefit for Blood Sugar

Strongest evidence first.

Published research: Blood Sugar. Study design is not a certainty grade.
Compound	Study designs	Reported findings
FenugreekResearch score 80/100 · Strong	5 systematic reviews/meta-analyses + 1 randomised trial — 6 studies	17/20 outcomes showed benefit Fasting blood glucose (FBG) — blood sugar after not eatingReported a benefit — see exact figuresbenefit2023 study ↗ Exact figures -28.99 (p < 0.05) n=3130 · Follow-up: Not reported · Sample (as reported): 3130 · Recorded unit: Not reported · 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. · Systematic Review · systematic-review · PMID 37451111 Fasting blood glucose (FBG) — blood sugar after not eatingReported a benefit — measurement not reportedbenefit2023 study ↗ Exact figures n=706 · Follow-up: Not reported · Sample (as reported): 706 · Recorded unit: Not reported · The Effect of Fenugreek in Type 2 Diabetes and Prediabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. · Systematic Review · systematic-review · PMID 37762302 High-density lipoprotein cholesterol — 'good' cholesterol21.7% increase compared with the start of the studybenefit2019 study ↗ Exact figures 21.7%; 37.8 ± 1.51 (P < 0.001) n=57 · Follow-up: one month · Sample (as reported): 57 · Recorded unit: Not reported · Antidiabetic Effect of Fenugreek Seed Powder Solution (Trigonella foenum-graecum L.) on Hyperlipidemia in Diabetic Patients. · Randomized Controlled Trial · rct · PMID 31583253 Low-density lipoprotein cholesterol — 'bad' cholesterol23.4% reduction compared with the start of the studybenefit2019 study ↗ Exact figures 23.4%; 137.9 ± 26.9 (P < 0.001) n=57 · Follow-up: one month · Sample (as reported): 57 · Recorded unit: Not reported · Antidiabetic Effect of Fenugreek Seed Powder Solution (Trigonella foenum-graecum L.) on Hyperlipidemia in Diabetic Patients. · Randomized Controlled Trial · rct · PMID 31583253 +16 more outcomes →
SpirulinaResearch score 66/100 · Moderate	4 systematic reviews/meta-analyses + 1 randomised trial — 5 studies	31/35 outcomes showed benefit Diastolic blood pressure0.42 lower, unit not reportedbenefit2025 study ↗ Exact figures -0.42 (95% CI: -0.81 to -0.02; p = 0.04) n=101 to 299 · Follow-up: Not reported · Sample (as reported): 101 to 299 · Recorded unit: Not reported · The Role of Chlorella and Spirulina as Adjuvants of Cardiovascular Risk Factor Control: A Systematic Review and Meta-Analysis of Randomised Controlled Trials · Meta-Analysis · meta-analysis · PMID 40289965 Fasting blood sugar (FBS)1.77 higher, unit not reportedbenefit2022 study ↗ Exact figures 1.77- · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · Effect of Microalgae Arthrospira on Biomarkers of Glycemic Control and Glucose Metabolism: A Systematic Review and Meta-analysis · Meta-Analysis · meta-analysis · PMID 34538515 BMI0.58 kg/m² lowerbenefit2025 study ↗ Exact figures -0.58 kg/m² (P = 0.001) n=35 trials · Follow-up: Not reported · Sample (as reported): 35 trials · Recorded unit: kg/m² · Spirulina's impacts on cardiovascular health: Insights from a systematic meta-analysis of RCT · Meta-Analysis · meta-analysis · PMID 40953712 DBP3.09 mmHg lowerbenefit2025 study ↗ Exact figures -3.09 mmHg (P < 0.001) n=35 trials · Follow-up: Not reported · Sample (as reported): 35 trials · Recorded unit: mmHg · Spirulina's impacts on cardiovascular health: Insights from a systematic meta-analysis of RCT · Meta-Analysis · meta-analysis · PMID 40953712 +31 more outcomes →
PsylliumResearch score 48/100 · Limited	3 systematic reviews/meta-analyses — 3 studies	9/15 outcomes showed benefit Fasting blood sugar (FBS)6.89 lower, unit not reportedbenefit2024 study ↗ Exact figures -6.89 (95% CI: -10.62, -3.16; p < .001) n=962 · Follow-up: Not reported · Sample (as reported): 962 · Recorded unit: Not reported · The effect of psyllium on fasting blood sugar, HbA1c, HOMA IR, and insulin control: a GRADE-assessed systematic review and meta-analysis of randomized controlled trials · Systematic Review · systematic-review · PMID 38844885 Fasting blood sugar31.7 ml/dl lowerbenefit2020 study ↗ Exact figures -31.71 ml/dl (95% CI [-50.04, -13.38]) n=395 · Follow-up: Not reported · Sample (as reported): 395 · Recorded unit: ml/dl · The effect of psyllium consumption on weight, body mass index, lipid profile, and glucose metabolism in diabetic patients: A systematic review and dose-response meta-analysis of randomized controlled trials · Meta-Analysis · meta-analysis · PMID 31919936 Fasting blood glucose in people treated for type 2 diabetes — blood sugar after not eating37 mg/dL lowerbenefit2015 study ↗ Exact figures -37.0 mg/dL (P < 0.001) · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: mg/dL · Psyllium fiber improves glycemic control proportional to loss of glycemic control: a meta-analysis of data in euglycemic subjects, patients at risk of type 2 diabetes mellitus, and patients being treated for type 2 diabetes mellitus · Meta-Analysis · meta-analysis · PMID 26561625 Blood glucose in people with normal blood sugar (euglycaemic)No clear benefit found — measurement not reportedno benefit2015 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · Psyllium fiber improves glycemic control proportional to loss of glycemic control: a meta-analysis of data in euglycemic subjects, patients at risk of type 2 diabetes mellitus, and patients being treated for type 2 diabetes mellitus · Meta-Analysis · meta-analysis · PMID 26561625 +11 more outcomes →
ResveratrolResearch score 16/100 · Mixed/Weak	3 systematic reviews/meta-analyses — 3 studies	2/14 outcomes showed benefit Fasting blood glucose levels — blood sugar after not eatingNo clear difference (2 mg/dL higher)no benefit2020 study ↗ Exact figures 2 (P = 0.29) n=31 · Follow-up: four weeks to five weeks · Sample (as reported): 31 · Recorded unit: mg/dL · Resveratrol for adults with type 2 diabetes mellitus · Meta-Analysis · meta-analysis · PMID 31978258 Fasting blood sugarNo clear benefit found — measurement not reportedno benefit2026 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · The effects of resveratrol on glycemic indices and lipid profile in patients with type 2 diabetes: an umbrella review and meta-analysis · Systematic Review · systematic-review · PMID 42268476 Glycated hemoglobin (HbA1c), short-term trials — average blood sugar over about 3 months1.05 % lowerbenefit2021 study ↗ Exact figures -1.05% (95% CI: -2.09%, -0.02%; n = 6) · Follow-up: short term (<12 wk) · Sample (as reported): Not reported · Recorded unit: % · The effects of resveratrol supplementation in patients with type 2 diabetes, metabolic syndrome, and nonalcoholic fatty liver disease: an umbrella review of meta-analyses of randomized controlled trials · Meta-Analysis · meta-analysis · PMID 34320173 Low-density lipoprotein-cholesterol (LDL-C) — 'bad' cholesterolReported a benefit — measurement not reportedbenefit2026 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · The effects of resveratrol on glycemic indices and lipid profile in patients with type 2 diabetes: an umbrella review and meta-analysis · Systematic Review · systematic-review · PMID 42268476 +10 more outcomes →
NMNResearch score 21/100 · Mixed/Weak	2 systematic reviews/meta-analyses + 2 randomised trials — 4 studies	3/21 outcomes showed benefit Blood NAD levelsReported a benefit — measurement not reportedbenefit2025 study ↗ Exact figures n=513 · Follow-up: Not reported · Sample (as reported): 513 · Recorded unit: Not reported · Efficacy of oral nicotinamide mononucleotide supplementation on glucose and lipid metabolism for adults: a systematic review with meta-analysis on randomized controlled trials · Systematic Review · systematic-review · PMID 39116016 Insulin-stimulated glucose disposal (hyperinsulinemic-euglycemic clamp)Reported a benefit — measurement not reportedbenefit2021 study ↗ Exact figures No figures reported · Follow-up: 10-week · Sample (as reported): Not reported · Recorded unit: Not reported · Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women · Randomized Controlled Trial · rct · PMID 33888596 Skeletal muscle insulin signaling (phosphorylation of AKT and mTOR)Reported a benefit — measurement not reportedbenefit2021 study ↗ Exact figures No figures reported · Follow-up: 10-week · Sample (as reported): Not reported · Recorded unit: Not reported · Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women · Randomized Controlled Trial · rct · PMID 33888596 Fasting glucose — blood sugar after not eatingNo clear benefit found — measurement not reportedno benefit2025 study ↗ Exact figures n=513 · Follow-up: Not reported · Sample (as reported): 513 · Recorded unit: Not reported · Efficacy of oral nicotinamide mononucleotide supplementation on glucose and lipid metabolism for adults: a systematic review with meta-analysis on randomized controlled trials · Systematic Review · systematic-review · PMID 39116016 +17 more outcomes →
BerberineResearch score 70/100 · Strong	2 systematic reviews/meta-analyses + 1 randomised trial — 3 studies	13/14 outcomes showed benefit Blood glucose levelsReported a benefit — measurement not reportedbenefit2023 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · Berberine and health outcomes: An umbrella review. · Systematic Review · systematic-review · PMID 36999891 Blood lipidsReported a benefit — measurement not reportedbenefit2023 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · Berberine and health outcomes: An umbrella review. · Systematic Review · systematic-review · PMID 36999891 Fasting plasma glucose (FPG) — blood sugar after not eating0.54 mmol/L lowerbenefit2019 study ↗ Exact figures -0.54 (95% CI: -0.77 to -0.30) n=2,313 · Follow-up: Not reported · Sample (as reported): 2,313 · Recorded unit: mmol/L · Effects of berberine on blood glucose in patients with type 2 diabetes mellitus: a systematic literature review and a meta-analysis. · Meta-Analysis · meta-analysis · PMID 30393248 Postprandial plasma glucose (PPG) — blood sugar after eating or a sugar drink0.94 mmol/L lowerbenefit2019 study ↗ Exact figures -0.94 (95% CI: -1.27 to -0.61) n=2,313 · Follow-up: Not reported · Sample (as reported): 2,313 · Recorded unit: mmol/L · Effects of berberine on blood glucose in patients with type 2 diabetes mellitus: a systematic literature review and a meta-analysis. · Meta-Analysis · meta-analysis · PMID 30393248 +10 more outcomes →
GlycineResearch score 65/100 · Moderate	3 randomised trials — 3 studies	7/8 outcomes showed benefit Interferon-gamma level (rose with glycine, fell with placebo)43% increase compared with the start of the studybenefit2008 study ↗ Exact figures 43% n=Seventy-four · Follow-up: 3 months · Sample (as reported): Seventy-four · Recorded unit: Not reported · Glycine treatment decreases proinflammatory cytokines and increases interferon-gamma in patients with type 2 diabetes · Randomized Controlled Trial · rct · PMID 18852529 A1C levelsReported a benefit — measurement not reportedbenefit2008 study ↗ Exact figures n=Seventy-four · Follow-up: 3 months · Sample (as reported): Seventy-four · Recorded unit: Not reported · Glycine treatment decreases proinflammatory cytokines and increases interferon-gamma in patients with type 2 diabetes · Randomized Controlled Trial · rct · PMID 18852529 TNF-receptor I levels — a signal that drives inflammationReported a benefit — measurement not reportedbenefit2008 study ↗ Exact figures n=Seventy-four · Follow-up: 3 months · Sample (as reported): Seventy-four · Recorded unit: Not reported · Glycine treatment decreases proinflammatory cytokines and increases interferon-gamma in patients with type 2 diabetes · Randomized Controlled Trial · rct · PMID 18852529 Plasma glucose area responseReported a benefit — see exact figuresbenefit2002 study ↗ Exact figures > 50% n=Nine · Follow-up: 2-h · Sample (as reported): Nine · Recorded unit: Not reported · The metabolic response to ingested glycine · Randomized Controlled Trial · rct · PMID 12450897 +4 more outcomes →

Important: This page reflects observational, aggregate-only community reporting and independent published research. It is not medical advice, and it does not claim any compound treats, cures, or is effective for any condition. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or treatment.

No community reports published yet.

We publish high blood sugar results only once at least 10 people report on the same compound, so no individual report is ever shown.

Fenugreek
Research saysResearch score 80/100 · Strong6 of 6 studies reported at least one benefit
People reportNot published yet — needs 10 or more reports
Berberine
Research saysResearch score 70/100 · Strong3 of 3 studies reported at least one benefit
People reportNot published yet — needs 10 or more reports
Spirulina
Research saysResearch score 66/100 · Moderate5 of 5 studies reported at least one benefit
People reportNot published yet — needs 10 or more reports
Glycine
Research saysResearch score 65/100 · Moderate3 of 3 studies reported at least one benefit
People reportNot published yet — needs 10 or more reports