Home Ingredients Copper Gluconate
Antioxidant

Copper Gluconate

Evidence Level
Preliminary
2 Clinical Trials
5 Documented Benefits
1/5 Evidence Score

Copper gluconate is a water-soluble copper salt of gluconic acid supplying roughly 14% elemental copper. It is a common copper form in multivitamins and is approved as a food fortificant. No published study on this page tested copper gluconate itself; the cited research measured how the body absorbs dietary copper in general. Copper is an essential trace mineral and cofactor for enzymes in iron metabolism, antioxidant defense, connective-tissue cross-linking, and energy production. Dietary copper deficiency is rare in people eating a normal diet, so routine copper supplements are usually unnecessary. The main reason people add copper is to offset high-dose zinc, which competes with copper for absorption and can cause copper deficiency over time.

Studied Dose No cited study tested a dose of copper gluconate. Intakes here come from nutrition guidelines, not from trials: the adult RDA is 0.9 mg/day of elemental copper and the tolerable upper limit is 10 mg/day from all sources. Supplements typically supply 1 to 2 mg. People on high-dose zinc sometimes add roughly 1 mg of copper per 15 mg of zinc, which is common practice rather than a tested dose.
Active Compound Copper(II) gluconate, Cu(C6H11O7)2 — water-soluble organic salt and GRAS fortificant providing approximately 14% elemental copper by weight

Benefits

Supports healthy red blood cells

Copper-dependent ceruloplasmin helps load iron onto transferrin for transport to the bone marrow. Adequate copper status is needed for normal red blood cell formation. This is basic nutrition biochemistry rather than a trial result: none of the studies cited on this page measured blood counts or iron status, and copper deficiency is rare on a normal diet.

Supported by Trial 1, Trial 2

Supports antioxidant defense

Copper is essential for copper-zinc superoxide dismutase, a key antioxidant enzyme in the cytoplasm that neutralizes superoxide radicals. That is the enzyme's known biochemistry. No study cited on this page measured antioxidant status or oxidative stress in people taking copper gluconate.

Supported by Trial 1

Supports connective tissue and blood vessels

Copper activates lysyl oxidase, the enzyme that cross-links collagen and elastin in skin, bone, cartilage, and arterial walls. Adequate copper is required for this cross-linking step. No cited study tested whether copper supplements change skin, bone, joint, or blood vessel outcomes in people.

Supported by Trial 1

Balances high-dose zinc supplementation

Zinc and copper compete for absorption, and sustained high-dose zinc can lower copper status, so people on long-term high-dose zinc are often advised to add a small amount of copper. This rests on the known interaction between the two minerals; no study cited on this page tested copper gluconate alongside zinc.

Supported by Trial 1, Trial 2

Supports energy production

Copper is a core component of cytochrome c oxidase in the mitochondrial electron transport chain. Adequate copper is needed for normal cellular respiration. That describes the enzyme's role and is not evidence that taking copper makes people feel more energetic; no cited study measured energy, fatigue, or exercise capacity.

Supported by Trial 1

Mechanism of action

1

Ceruloplasmin ferroxidase activity

Ceruloplasmin, a copper-containing protein, oxidizes ferrous iron to the ferric form that binds transferrin. This step is needed for iron to leave storage sites, which is why severe copper deficiency can produce an anemia that looks like iron deficiency even when iron stores are normal. That kind of deficiency is uncommon and usually has a specific cause such as long-term high-dose zinc or a malabsorption problem.

2

Cu/Zn-SOD antioxidant catalysis

Copper in the active site of copper-zinc superoxide dismutase enables the conversion of superoxide radicals to hydrogen peroxide, a foundational antioxidant reaction in the cytoplasm that protects proteins, lipids, and DNA.

3

Cytochrome c oxidase electron transfer

Copper centers in cytochrome c oxidase (Complex IV) accept electrons and transfer them to molecular oxygen, completing the electron transport chain. Adequate copper is required for efficient mitochondrial ATP production.

4

Soluble salt absorption

Copper gluconate dissolves in the gut to release Cu2+, which is then absorbed in the small intestine. Stable-isotope studies of dietary copper, not of the gluconate salt specifically, show that the fraction absorbed is high at low intakes and falls as intake rises, reflecting tight control of copper balance by the body.

Clinical trials

1
Copper absorption at three levels of dietary copper (absorption study, not a health outcome trial)
PubMed

Controlled metabolic balance study using the stable isotope 65Cu to measure how much copper the body absorbs and retains in young men at low, adequate, and high copper intakes. It tracked mineral balance only, with no health outcome and no placebo comparison, and it did not test copper gluconate.

11 young men (metabolic unit).

Copper absorption rose to about 56% on a low-copper diet and fell to roughly 12% on a high-copper diet, with adequate intake near 36%. This shows the body tightly regulates how much copper it absorbs, and the authors used it to estimate roughly 0.8 mg/day as adequate for young men. It says nothing about immunity, heart health, antioxidant status, or any benefit of taking a copper supplement.

2
Copper absorption on a low-copper diet (absorption study, not a health outcome trial)
PubMed

Stable-isotope (65Cu) metabolic balance study measuring copper absorption, excretion, and retention in young men eating a low-copper diet. Like the study above, it followed mineral balance rather than any health outcome, and the copper came from the diet rather than from a gluconate supplement.

Young men consuming low dietary copper.

On low copper intake, fractional absorption increased and the body adjusted excretion to defend copper balance, confirming efficient adaptive uptake of dietary copper. The study did not test copper gluconate and did not measure any health outcome, so it cannot show a benefit of supplementing.

Side effects and drug interactions

Common Potential side effects

Generally well tolerated at supplemental doses within the 10 mg/day adult upper limit, but because dietary copper deficiency is rare, most people do not need a copper supplement at all.
Nausea, vomiting, or abdominal pain can occur at high doses, especially on an empty stomach.
Excess copper is toxic. Chronic intake above the 10 mg/day upper limit can cause liver injury.
People with Wilson's disease must avoid supplemental copper due to dangerous copper accumulation.
The interaction runs both ways: just as high-dose zinc causes copper deficiency, high-dose copper can lower zinc status.

Important Drug interactions

High-dose zinc (over about 40 mg/day) blocks copper absorption and can cause deficiency.
Copper chelators penicillamine and trientine for Wilson's disease are opposed by supplemental copper.
Antacids and proton pump inhibitors may reduce copper absorption; separate dosing.
High-dose vitamin C can modestly lower copper absorption when taken together.

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Frequently asked questions about Copper Gluconate

What is copper gluconate?

Copper gluconate is copper bound to gluconic acid, a water-soluble form commonly used in supplements and to balance zinc. It is one of the standard ways to supply small amounts of copper, though no published study cited here compared this specific salt against other copper forms.

Why take copper gluconate?

Most people do not need it. Copper deficiency is rare in people eating a normal diet, and the usual reason to add copper is to offset long-term high-dose zinc, which can drive copper status down. Copper's role in iron handling, connective tissue, and the antioxidant enzyme Cu/Zn-SOD is established nutrition biochemistry, not a demonstrated benefit of taking a copper supplement.

How much copper gluconate should I take?

Copper needs are small: the RDA is about 900 mcg per day. Supplements typically provide 1 to 2 mg of elemental copper, often paired with zinc. Avoid exceeding 10 mg per day from all sources.

Is copper gluconate safe?

At small supplemental amounts it is generally well tolerated. Excess copper is toxic: high doses can cause nausea, vomiting, and abdominal pain, and chronic excess can injure the liver. Stay within the 10 mg/day upper limit from all sources, and only supplement copper when there is a reason to, such as offsetting high-dose zinc. Anyone with Wilson's disease, an inherited copper-overload disorder, must avoid supplemental copper entirely.

What is Copper Gluconate used for?

Copper Gluconate is researched primarily for Antioxidant. Copper-dependent ceruloplasmin helps load iron onto transferrin for transport to the bone marrow. Adequate copper status is needed for normal red blood cell formation.

What is the recommended dosage of Copper Gluconate?

The clinically studied dose is No cited study tested a dose of copper gluconate. Intakes here come from nutrition guidelines, not from trials: the adult RDA is 0.9 mg/day of elemental copper and the tolerable upper limit is 10 mg/day from all sources. Supplements typically supply 1 to 2 mg. Always follow the product label and check with a healthcare provider for personal advice.

Is Copper Gluconate safe, and does it have side effects?

For most healthy adults, Copper Gluconate is well tolerated at studied doses. Reported effects can include: Generally well tolerated at supplemental doses within the 10 mg/day adult upper limit, but because dietary copper deficiency is rare, most people do not need a copper supplement at all. Nausea, vomiting, or abdominal pain can occur at high doses, especially on an empty stomach. It may also interact with some medications. Copper Gluconate is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Copper Gluconate interact with any medications?

Possible interactions include: High-dose zinc (over about 40 mg/day) blocks copper absorption and can cause deficiency. Copper chelators penicillamine and trientine for Wilson's disease are opposed by supplemental copper. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Copper Gluconate?

NutraSmarts rates the evidence for Copper Gluconate as Preliminary (1 out of 5). It is backed by 2 clinical trials and 3 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(3 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Turnlund JR, Keyes WR, Anderson HL, Acord LL. Copper absorption and retention in young men at three levels of dietary copper by use of the stable isotope 65Cu. Am J Clin Nutr. 1989;49(5):870-8. doi: 10.1093/ajcn/49.5.870.PubMedUsed to support: A metabolic balance study showing that copper absorption is high at low intakes and falls at high intakes. It describes how the body handles dietary copper; it did not test copper gluconate and did not measure any health outcome.
  2. Turnlund JR, Keyes WR, Peiffer GL, Scott KC. Copper absorption, excretion, and retention by young men consuming low dietary copper determined by using the stable isotope 65Cu. Am J Clin Nutr. 1998;67(6):1219-25. doi: 10.1093/ajcn/67.6.1219.PubMedUsed to support: Shows that on a low-copper diet the body absorbs a larger fraction of copper and excretes less. This is again an absorption and balance study, not a test of copper gluconate or of any health benefit.
  3. Baker DH. Cupric oxide should not be used as a copper supplement for either animals or humans. J Nutr. 1999;129(12):2278-9. doi: 10.1093/jn/129.12.2278.PubMedUsed to support: This reference is about a different compound. It is a short review arguing that cupric oxide should not be used as a copper supplement because it is poorly absorbed. It is a warning about cupric oxide and contains no data on copper gluconate.