Supplement Label Index

Zinc Oxide vs. Zinc Gluconate

Among 8,549 on-market zinc products with an identifiable primary form, 29% use Zinc Oxide (2,481 products) and 15.1% use Zinc Gluconate (1,289).

Zinc OxideZinc Gluconate
Quality tierTier 3Tier 2
Zinc by weight80.3%14.3%
Share of market29%15.1%
On-market products2,4811,289
Median declared dose15 elemental mg
middle half: 8–23.6
7.5 elemental mg
middle half: 3–15
Most common brandsNew Chapter, GNC Mega Men, GNC Women's Ultra MegaDC, Wonder Laboratories, Nature's Way

Doses are declared per serving in elemental mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).

Why Zinc Oxide is tier 3

Isotope-tracer RCT: absorption 49.9%, significantly lower than citrate/gluconate; 3/15 subjects showed little/no absorption.

Source: Wegmuller R et al. 2014, PMID 24259556

Why Zinc Gluconate is tier 2

Absorption 60.9%, statistically comparable to citrate, both significantly better than oxide.

Source: Wegmuller R et al. 2014, PMID 24259556

Tiers summarize published comparative bioavailability or outcome evidence for each form (see methodology). This page describes the market; it is not a recommendation to take either form. Talk to a clinician about what's right for you.

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