Fasting Glucose: what it means.
Written to our editorial standards · reviewed against published research· Updated 27 Jun 2026
Typical reference bands (mg/dL)
Optimalunder 90 mg/dL
Borderline100-126 mg/dL
Highover 126 mg/dL
Ranges vary by laboratory, age, and sex, your lab's own reference range always takes precedence.
Common causes
- Insulin resistance, often with excess fat around the middle
- Low activity and a refined-carb-heavy diet
- Poor sleep and chronic stress
- Family history
What it can feel like
- Often none early on
- Later: increased thirst, frequent urination, and fatigue
Who should test
Recommended with a family history, excess weight, or signs of metabolic syndrome. A fasting glucose of 100 to 125 mg/dL is the prediabetic range.
Supplements that help lower Fasting Glucose
Evidence-led, and only a piece of the picture, diet, lifestyle, and your clinician matter most.
Berberine, chromium, and alpha-lipoic acid support insulin sensitivity and glucose uptake, alongside the larger levers of diet, movement, and weight.
Shop the top pick for fasting glucose
Recommended
Thorne, Berberine 500mg
60 capsules · ~$32 · ★ 4.7
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Common questions
What does a high Fasting Glucose mean?
Common drivers include insulin resistance, often with excess fat around the middle; low activity and a refined-carb-heavy diet; poor sleep and chronic stress. A result outside the optimal range is best read in context: discuss it with your clinician, who can weigh the full picture and your lab's own reference range.
What supplements help lower Fasting Glucose?
Evidence-led options include Berberine HCl, Chromium Picolinate, Alpha-Lipoic Acid. They support, but don't replace, diet, lifestyle, and medical care.
Educational use only, not medical advice or diagnosis. Always interpret lab results with a qualified clinician.