Cupric Oxide vs. Copper Citrate
Among 3,989 on-market copper products with an identifiable primary form, 12% use Cupric Oxide (478 products) and 10.6% use Copper Citrate (423).
| Cupric Oxide | Copper Citrate | |
|---|---|---|
| Quality tier | Tier 3 | Tier 2 |
| Copper by weight | 79.9% | 35.3% |
| Share of market | 12% | 10.6% |
| On-market products | 478 | 423 |
| Median declared dose | 2,000 elemental mcg middle half: 1,600–2,000 | 1,000 elemental mcg middle half: 334–2,000 |
| Most common brands | GNC Women's Ultra Mega, GNC Mega Men, Vitamin World | Ultima, Metagenics, Source Naturals |
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 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
Why Copper Citrate is tier 2
Marketed as a bioavailable organic copper salt; no direct human comparative bioavailability RCT located.
Source: 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 copper comparisons
- Copper Gluconate vs. Copper Amino Acid Chelate
- Copper Gluconate vs. Cupric Oxide
- Copper Gluconate vs. Copper Citrate
- Copper Gluconate vs. Copper Sulfate
- Copper Amino Acid Chelate vs. Cupric Oxide
- Copper Amino Acid Chelate vs. Copper Citrate
- Copper Amino Acid Chelate vs. Copper Sulfate
- Cupric Oxide vs. Copper Sulfate
- Copper Citrate vs. Copper Sulfate