Zinc
Of 13,396 on-market zinc products in the January 2026 DSLD dump, the median declared dose is 10 elemental mg, and 31.9% list unspecified/undisclosed form as the primary form.
Form share
Of 12,555 products with an identifiable primary form, here is the share held by each form of Zinc on the market today.
| Form | Quality tier | n | Share |
|---|---|---|---|
| unspecified/undisclosed form | Unrated | 4,006 | 31.9% |
| Zinc Oxide | Tier 3 | 2,481 | 19.8% |
| Zinc Citrate | Tier 1 | 2,223 | 17.7% |
| Zinc Gluconate | Tier 2 | 1,289 | 10.3% |
| Zinc Bisglycinate Chelate | Unrated | 833 | 6.6% |
| Zinc Amino Acid Chelate | Tier 2 | 695 | 5.5% |
| Zinc Picolinate | Tier 2 | 598 | 4.8% |
| Zinc Sulfate | Tier 2 | 430 | 3.4% |
Form share over time
Entry-year breakdown of the top forms, 2012–2025.
Dose distribution
Deciles of declared dose per serving (elemental mg), among 12,314 products with a disclosed amount, against the RDA of 11 and UL of 40.
- 8.0% of products fall below the fairy-dust threshold (2 mg, 20% of the studied low dose).
- 0.8% of products don't disclose an amount because Zinc is declared inside a proprietary blend.
By dosage form
By target group
Top brands
| Brand | Products |
|---|---|
| Douglas Laboratories | 310 |
| Nature's Way | 186 |
| Centrum | 184 |
| Wonder Laboratories | 156 |
| DC | 150 |
| Source Naturals | 139 |
| NOW | 122 |
| Emergen-C | 121 |
| Pure Encapsulations | 120 |
| MegaFood | 118 |
| Nature Made | 116 |
| Higher Nature | 116 |
| Life Extension | 111 |
| Metagenics | 110 |
| Bluebonnet | 106 |
| The Vitamin Shoppe | 104 |
| XYMOGEN | 93 |
| New Chapter | 92 |
| GNC Mega Men | 89 |
| Puritan's Pride | 87 |
| Bayer One A Day | 84 |
| Vitamin World | 83 |
| Solgar | 82 |
| Nutri-West | 79 |
| NaturesPlus | 79 |
Forms explained
Label discloses only "Zinc" with no salt form.
Elemental fraction: 32.1% (Zn3(C6H5O7)2 x 2H2O, dihydrate (USP monograph, NLT 31.3% Zn dried basis))
Isotope-tracer RCT: absorption 61.3%, comparable to gluconate, significantly higher than oxide.
Source: Wegmuller R et al. 2014, J Nutr 144(2):132-136, PMID 24259556
Elemental fraction: 80.3% (ZnO, anhydrous (no stable hydrate))
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
Elemental fraction: 14.3% (Zn(C6H11O7)2, anhydrous (standard commercial/USP form))
Absorption 60.9%, statistically comparable to citrate, both significantly better than oxide.
Source: Wegmuller R et al. 2014, PMID 24259556
No specific human isotope-absorption study for the generic category (distinct from bisglycinate specifically).
Source: uncertain -- needs review
Elemental fraction: 21.1% (Zn(C6H4NO2)2, anhydrous)
Raised hair/urine/erythrocyte zinc more than citrate or gluconate in a small (n=15) crossover using indirect tissue markers; the popular "best absorbed" claim is more equivocal than commonly stated.
Source: Barrie SA et al. 1987, Agents Actions 21(1-2):223-228
Elemental fraction: 30.6% (Zn(C2H4NO2)2, anhydrous bisglycinate)
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
Elemental fraction: 22.7% (ZnSO4 x 7H2O, heptahydrate (classic OTC form; a monohydrate at 0.364 also exists commercially -- check specific labels))
WHO/UNICEF-recommended form for diarrhea-management zinc dosing and the classic reference standard in absorption literature, but no specific head-to-head human isotope-absorption percentage vs citrate/gluconate/picolinate was verified.
Source: uncertain -- needs review (WHO/UNICEF clinical-use basis, not a specific bioavailability study)
Reference values
- RDA (adult): 11 elemental mg — 11mg (men); 8mg (women)
- Tolerable Upper Intake Level (adult): 40 elemental mg — Based on reduction in erythrocyte Cu-Zn superoxide dismutase activity
- Studied clinical dose range: 10–50 mg
- Wegmuller R et al. 2014, J Nutr 144(2):132-136, PMID 24259556 -- double-isotope RCT (n=15) crossover, 10mg elemental Zn as citrate/gluconate/oxide; citrate (61.3%) and gluconate (60.9%) absorption significantly higher than oxide (49.9%, P<0.01). High end reflects Barrie et al. 1987 (50mg elemental Zn/day).