Copper

Copper (Cupric Oxide)

Also known as: Cupric oxide, Copper gluconate

Vitamin & Mineral

Content by: OpenSupplement Editorial Team | Medical review: pending | Last updated: April 13, 2026

Evidence ★★★★☆4/5

Best for

Immune

Typical dose2 mg/day (AREDS2 dose)

SafetyNo significant concerns

Onset8+ weeks

Cost$5-8/mo

References3 studies cited

TL;DR

Essential trace mineral for collagen and red blood cell production
Moderate evidence for bone health and heart function
Mandatory when taking high-dose Zinc supplements
Dangerous in excess; can cause oxidative stress
Very cheap: ~$5-8/month
Best for: Balancing zinc, preventing anemia

What it is

Copper is required for the enzyme that 'links' collagen and elastin together, giving your skin and blood vessels their strength. It is also essential for the transport of iron. If you are low in copper, you can become anemic even if you have enough iron.

What the research says

Macular degenerationRelevance: High

Evidence

4/5

Onset speed

1/5

Typical dose: 2 mg/day (AREDS2 dose)

Copper (2mg) is included in AREDS2 [ref1] not for direct eye benefits, but to prevent copper deficiency caused by the formula's high zinc content (80mg). The AREDS2 researchers included it after the original AREDS study raised concerns about zinc-induced copper depletion [ref2]. ^[1]^[2]^[3]

DISCLAIMER: The information on this page is for educational purposes only and has not been evaluated by the Food and Drug Administration. This content is not intended to diagnose, treat, cure, or prevent any disease. Consult a qualified healthcare professional before using any dietary supplement, especially if you are pregnant, nursing, taking medication, or have a medical condition.

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Copper on Amazon

$5-8/mo (estimated)

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Safety

Narrow therapeutic window. Too much copper (Zinc-to-Copper ratio imbalance) can cause oxidative damage and is associated with a higher risk of Alzheimer's. Only supplement if you are taking zinc or have a confirmed deficiency.

Interactions

Zinc: High-dose zinc (50mg+) blocks copper absorption. Always take them together (approx 15:1 ratio).

Dosing

Standard Dose: 1-2 mg daily. Form: Copper Gluconate or Sebacate.

Cost

Dirt cheap. $5-8 per month.

The bottom line

Copper is the 'silent partner' to zinc. Don't take it alone unless necessary, but don't forget it if you are taking an immune-boosting zinc supplement.

References

Age-Related Eye Disease Study 2 Research Group. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial. JAMA. 2013;309(19):2005-15.
RCTMacular degenerationPubMed →
Chew EY, Clemons T, SanGiovanni JP, et al. The Age-Related Eye Disease Study 2 (AREDS2): study design and baseline characteristics (AREDS2 report number 1). Ophthalmology. 2012;119(11):2282-9.
RCTMacular degenerationPubMed →
Office of Dietary Supplements. Copper - Health Professional Fact Sheet. National Institutes of Health.
NIH Fact SheetMacular degenerationSource →

Sources for this page include published meta-analyses, systematic reviews, and NIH dietary supplement fact sheets. All claims reflect the evidence as of early 2026.

This is not medical advice. Consult your healthcare provider before starting any supplement, especially if you take medications.