Quick answer
Adults need 900 mcg (0.9 mg) of copper a day, 1,000 mcg in pregnancy and 1,300 mcg while breastfeeding, and most get that from food. Supplements range from a few micrograms to 15 mg. The US upper limit is 10 mg a day, and European scientists expect no copper buildup at 5 mg a day.1,2,3
Key facts
- Adults in the United States average 1,400 to 1,700 mcg of copper a day once supplements are counted.2
- In a 12-week trial, 10 mg a day as copper gluconate did not change blood copper or liver enzymes in 7 people.4
- In a 90-day study of young men, copper absorption fell from about 56% on a low-copper diet to 12% on a high one.5
- European scientists set an acceptable daily intake of 0.07 mg per kg of body weight, about 4.9 mg for a 70 kg adult.3
Recommended amounts and upper limits by age
| Age or stage | Recommended amount | Upper limit |
|---|---|---|
| Birth to 6 months | 200 mcg (adequate intake) | Not set |
| 7 to 12 months | 220 mcg (adequate intake) | Not set |
| 1 to 3 years | 340 mcg | 1,000 mcg |
| 4 to 8 years | 440 mcg | 3,000 mcg |
| 9 to 13 years | 700 mcg | 5,000 mcg |
| 14 to 18 years | 890 mcg | 8,000 mcg |
| 19 years and older | 900 mcg | 10,000 mcg |
| Pregnancy | 1,000 mcg | 8,000 mcg under 19, 10,000 mcg from 19 |
| Breastfeeding | 1,300 mcg | 8,000 mcg under 19, 10,000 mcg from 19 |
One milligram is 1,000 micrograms, so the adult need of 900 mcg is the 0.9 mg Daily Value shown on labels, and the adult upper limit of 10,000 mcg is 10 mg. For infants, breast milk, formula and food should be the only sources of copper.2
What you probably get already
Typical American diets meet or exceed the recommended amount: men average 1,400 mcg a day from food and women 1,100 mcg. That is why LiverTox describes copper supplements as rarely needed.2,6
About 6% to 15% of adults who do not take a supplement with copper get less than the estimated average requirement, compared with 2.2% to 7.2% of those who do.2
Why taking more does not mean absorbing more
The body absorbs a smaller share of copper as intake rises: about 75% of the copper in a diet that supplies 400 mcg a day, and about 12% at 7.5 mg a day.2,5
A 90-day study in 11 young men shows the effect within one group of people: they absorbed about 56% of their copper on a diet with 0.785 mg a day, 36% with 1.68 mg and 12% with 7.53 mg. Most of them could reach copper balance on 0.8 mg a day.5
This regulation has limits at the low end. In another 90-day study, the body absorbed more and lost less when young men ate a low-copper diet, but at 0.38 mg a day that was not enough to keep their copper status up.7
High doses
In a 12-week double-blind trial, 7 people who took 10 mg of copper a day as copper gluconate had no change in blood, urine or hair copper or in liver enzymes, and reported no more stomach complaints than those on placebo.4
European scientists concluded in 2023 that no copper builds up in the body at intakes of 5 mg a day, and set an acceptable daily intake of 0.07 mg per kg of body weight from all sources.3
The US upper limit of 10 mg a day was set from the amounts linked with liver damage. The European review looked instead for the intake at which copper starts to build up in the body, and found none expected at 5 mg a day. Long-term intakes above the limit can damage the liver.1,2,3
If you also take zinc
Zinc and copper compete. NIH says 50 mg of zinc a day or more for weeks can interfere with copper absorption, and a marker of copper status fell with about 60 mg of zinc a day within 10 weeks. That is one reason the adult upper limit for zinc is set at 40 mg a day.2,8
Questions people ask
Is 2 mg of copper a day too much?
It is more than the 0.9 mg adults need but well under the 10 mg upper limit, and under the 5 mg a day at which European scientists expect no copper buildup. Food adds about 1.1 to 1.4 mg a day on average, so count that too.2,3
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Sources
- Office of Dietary Supplements, National Institutes of Health. Copper: Fact Sheet for Consumers. Updated October 18, 2022. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Copper: Fact Sheet for Health Professionals. Updated October 18, 2022. Opened 2026-10-07.
- EFSA Scientific Committee, More SJ, et al. Re-evaluation of the existing health-based guidance values for copper and exposure assessment from all sources. EFSA J. 2023;21(1):e07728. Opened 2026-10-07.
- Pratt WB, Omdahl JL, Sorenson JR. Lack of effects of copper gluconate supplementation. Am J Clin Nutr. 1985;42(4):681-682. Opened 2026-10-07.
- 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):870-878. Opened 2026-10-07.
- Copper. In: LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012-. Updated October 30, 2017. Opened 2026-10-07.
- 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):1219-1225. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Zinc: Fact Sheet for Health Professionals. Updated January 6, 2026. Opened 2026-10-07.
- Olivares M, Araya M, Pizarro F, Uauy R. Nausea threshold in apparently healthy individuals who drink fluids containing graded concentrations of copper. Regul Toxicol Pharmacol. 2001;33(3):271-275. Opened 2026-10-07.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.