BioStacks
Kirkland Signature

C 1000 mg

1 Tablet · 500 servings

iHerbAmazon
33 / 100Poor

Best for

Immune

Score Breakdown

Formulation
38
Safety
87
Final score
33/100

Ingredients (2)

Vitamin C

100%

Dose

1000 mg

Target

250–2000 mg

Form

Not listed

Citrus Bioflavonoid Complex

40%

Dose

100 mg

Target

250–1000 mg

Form

—

Other Ingredients (12)

MaltodextrinBinder

Spikes blood sugar faster than table sugar (glycemic index 85–105). Research links it to gut bacteria changes that may promote intestinal inflammation (Nickerson et al. 2015). Used as a cheap filler — adds nothing beneficial.

Magnesium StearateLubricant

A salt of stearic acid used as a lubricant in tablet and capsule production

Rose Hips (base)Botanical Base

Dried fruit of Rosa canina used as a whole-food base in vitamin C formulas; contributes trace natural vitamin C

Silicon DioxideAnti-caking

Fine silica powder used to prevent clumping

Ascorbic AcidAntioxidant

Vitamin C used as an antioxidant preservative in supplements to prevent oxidation

Citrus BioflavonoidsAntioxidant

Natural flavonoid compounds (hesperidin, naringin, rutin) extracted from citrus fruit peel and pulp

Croscarmellose SodiumDisintegrant

Cross-linked cellulose derivative used as a superdisintegrant

Guar GumThickener

Natural thickener derived from guar beans

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Sources & Scoring

Nutrient data (RDA, UL, and safety thresholds) sourced from: NIH Office of Dietary Supplements and National Academies Dietary Reference Intakes (DRI).

This is not medical advice. Consult a healthcare provider before making changes to your supplement routine.

The score analyzes what's on the label: ingredient doses vs. clinical ranges, chemical forms, evidence levels, and known interactions. It does not verify label accuracy or test for contaminants — for that, look for third-party certifications like USP or NSF.

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