Supplement Label Index

Copper Amino Acid Chelate vs. Cupric Oxide

Among 3,989 on-market copper products with an identifiable primary form, 33.8% use Copper Amino Acid Chelate (1,347 products) and 12% use Cupric Oxide (478).

Copper Amino Acid ChelateCupric Oxide
Quality tierTier 1Tier 3
Copper by weight30.0%79.9%
Share of market33.8%12%
On-market products1,347478
Median declared dose1,000 elemental mcg
middle half: 500–2,000
2,000 elemental mcg
middle half: 1,600–2,000
Most common brandsDouglas Laboratories, NOW, BluebonnetGNC Women's Ultra Mega, GNC Mega Men, Vitamin World

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

Why Copper Amino Acid Chelate is tier 1

The specific form used in the one human RCT with a defined copper chelate that demonstrated a measurable physiological effect (raised SOD1/ceruloplasmin).

Source: DiSilvestro RA et al. 2012, Metabolism 61(9):1242-6, PMID 22444781

Why Cupric Oxide is tier 3

Provides essentially no bioavailable copper relative to CuSO4 per chick/rat data.

Source: Baker DH. 1999, J Nutr 129:2278-9, PMID 10573563

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 copper comparisons