Supplements, reviewed against the evidence
Six supplements sold for blood sugar, each reviewed the same way: what the pooled trials actually found, how good that evidence is, and who should not take it. One of the six we recommend against outright.
Safety comes before commerce on every page here, structurally — interactions and contraindications appear above any link, never below or folded away. The readers most likely to arrive on these pages are already taking medication.
What we can say and sell where you are
Supplement claims are permitted here with substantiation, and we carry commercial links. We still describe the evidence rather than promise a result.
Supplements
- Berberine
The supplement with the largest measured glucose effect on this page, and the largest interaction risk. Both halves matter.
Strength of evidence: Some support
Updated 2026-08-07 - Magnesium
Cheap, well tolerated, and genuinely deficient in a lot of people. The glucose case is weaker than the popular one, and slower.
Strength of evidence: Weak
Updated 2026-08-07 - Chromium
Twenty-five years of trials that keep disagreeing with each other. The disagreement is the finding.
Strength of evidence: Weak
Updated 2026-08-07 - Cinnamon
The most-recommended glucose supplement on the internet, and the one with the clearest negative verdict from a systematic review.
Strength of evidence: Not supported
Updated 2026-08-07 - Inositol
The one supplement here with a specific population behind it rather than a general glucose claim — and outside that population, very little.
Strength of evidence: Weak
Updated 2026-08-07 - Apple cider vinegar
The one supplement here whose effect you can genuinely watch on a sensor — which is not the same as it improving your health.
Strength of evidence: Weak
Updated 2026-08-07
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.
Why glucose matters