Supplement Label Index

Zinc Oxide vs. Zinc Bisglycinate Chelate

Among 8,549 on-market zinc products with an identifiable primary form, 29% use Zinc Oxide (2,481 products) and 9.7% use Zinc Bisglycinate Chelate (833).

Zinc OxideZinc Bisglycinate Chelate
Quality tierTier 3Unrated
Zinc by weight80.3%30.6%
Share of market29%9.7%
On-market products2,481833
Median declared dose15 elemental mg
middle half: 8–23.6
11 elemental mg
middle half: 6.85–15
Most common brandsNew Chapter, GNC Mega Men, GNC Women's Ultra MegaXYMOGEN, MegaFood, Bluebonnet

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 Bisglycinate Chelate is unrated

Comparative advantage over gluconate shown in a rat model (~49% vs ~42% absorption with phytate present), not confirmed in a human trial.

Source: PMID 16684142 (animal study, not human) -- uncertain, needs review

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.

Other zinc comparisons