The Link Between Copper Toxicity and IUDs

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Fact-Checked by: Dr. Karen Viera, PhD.

If you are using or thinking of using a copper intrauterine device (IUD) to prevent pregnancy, there are several factors that should be considered. Many women who use copper IUDs have no problems; however, there have been reports of potential side effects and copper toxicity from using an IUD. Copper IUD toxicity is a serious condition that can cause kidney conditions, liver damage, heart failure, brain damage, or in severe cases, fatality.

How Copper IUDs Work

Copper IUDs (such as Paragard) mainly prevent pregnancy by continuous release of copper ions into the uterus. These copper ions kill sperm that enter the uterus. While copper is a mineral that is required for human health, too much can be harmful1. This ionic copper can be directly absorbed into the uterine lining, causing damage to local cells and increasing the risk of other negative side effects2. Copper ions can also interact with other molecules that naturally occur in the uterus (such as oxygen) to create harmful reactive oxygen species and cause damage to the uterus and cervix. Perhaps most concerningly, some copper IUDs have been associated with copper toxicity.

Dangers of Copper IUDS: Side Effects 

The “birth control” effect of copper IUDs is dependent on the copper ions released by the degradation of the copper in the IUD. The more copper ions that are released, the better the birth control effect. According to research, there is a very high release of copper ions in the first few days after insertion3. This burst of copper ions is thought to be the main driver of the associated harmful effects, which can include heavy bleeding and pelvic pain. The main side effect of copper IUD use is increased bleeding during your period4. Abnormal uterine bleeding may include too much blood, a short menstrual cycle, a long menstrual cycle, or irregular bleeding. Excess bleeding may continue, even after long-term use of a copper IUD. It has been reported that there are more copper ions in the uteruses of women who suffer from too much bleeding5.

Copper IUDs rarely cause toxic effects outside of the uterus2. However, they can cause non-toxic changes throughout the body. Some women report depression while using a copper IUD. One study looked at the serum of a group of women before they had an IUD inserted and three months later6. Levels of copper and zinc in their serum were significantly (but not toxically) increased at three months, compared to before copper IUD insertion. All IUDs cause local inflammatory reactions in the uterus. It is the local inflammation, combined with the sperm-killing effect of the copper ions, that prevents pregnancy. The copper ions that dissolve off IUDs can spread throughout the uterus, causing a buildup of toxic compounds7. In women, the entire genital tract can be affected by inflammation.

One way that copper ions cause damage is by creating reactive oxygen species, such as superoxide radicals, hydrogen peroxide, and hydroxyl radicals. These molecules cause oxidative damage and can be toxic at high levels. One group reported that markers of oxidative stress and liver damage were higher in women with IUDs, and that levels of these markers increased over the course of copper IUD use8. Another study showed that levels of reactive oxygen species can continue to increase up to twelve weeks after insertion of the copper IUD9. Other research has shown that the lining of the uterus and cervix could be harmed by the oxidative stress caused by a copper IUD10.

Potential Toxicity of Copper IUDs

Excess copper in the body causes a kind of metal poisoning known as copper toxicity. Copper toxicity can be caused by a variety of situations, including copper poisoning from IUD use. Even though all copper IUDs have been thoroughly tested, some are safer than others2. Research shows that the concentration of copper is higher in the bodies of women with copper IUDs. One study reported that some copper IUDs are mildly to severely toxic to cells, even when limited to short periods of contact3. For some of the IUDs tested, a decrease in overall health of the cells was reported. Another study focused on testing the possible toxic effects on ovarian cells and their DNA11. They observed that copper ions caused ovarian cell death, DNA damage, decreased the ability of cells to make energy, and decreased overall cell health.

If you experience any of the following copper toxicity symptoms after IUD implantation, contact your doctor:

  • Headaches
  • Fever
  • Passing out
  • Nausea or vomiting
  • Blood in your vomit
  • Diarrhea
  • Black stool
  • Abdominal cramps
  • Brown ring-shaped markings in your eyes or yellowing of the eyes or skin
  • Suddenly feeling anxious or irritable
  • Depression 
  • Trouble paying attention
  • Sudden changes in your mood


What do I do if I think I have copper toxicity from using a copper IUD?

If you are experiencing symptoms that may be indicative of copper toxicity, call your healthcare provider immediately to get their opinion.

If I think I have copper toxicity, should I remove my copper IUD?

You should never remove an IUD yourself. An IUD should always be removed by a healthcare professional.


  1. Crandell L, Mohler N. A Literature Review of the Effects of Copper Intrauterine Devices on Blood Copper Levels in Humans. Nurs Womens Health. 2021;25(1):71-81. doi:10.1016/j.nwh.2020.11.003
  2. Hu LX, Hu SF, Rao M, et al. Studies of acute and subchronic systemic toxicity associated with a copper/low-density polyethylene nanocomposite intrauterine device. Int J Nanomedicine. 2018;13:4913-4926. Published 2018 Aug 31. doi:10.2147/IJN.S169114
  3. Hu LX, He J, Hou L, et al. Biological evaluation of the copper/low-density polyethylene nanocomposite intrauterine device. PLoS One. 2013;8(9):e74128. Published 2013 Sep 18. doi:10.1371/journal.pone.0074128
  4. 3 Hardeman J, Weiss BD. Intrauterine devices: an update. Am Fam Physician. 2014;89(6):445-450.
  5. Li L, Li J, Li N, Zhang Y, Feng X. Analysis of the reason of abnormal uterine bleeding induced by copper corrosion of IUD Cu. Clin Exp Obstet Gynecol. 2016;43(6):883-886.
  6. Imani S, Moghaddam-Banaem L, Roudbar-Mohammadi S, Asghari-Jafarabadi M. Changes in copper and zinc serum levels in women wearing a copper TCu-380A intrauterine device. Eur J Contracept Reprod Health Care. 2014;19(1):45-50. doi:10.3109/13625187.2013.856404
  7. Ortiz ME, Croxatto HB. Copper-T intrauterine device and levonorgestrel intrauterine system: biological bases of their mechanism of action. Contraception. 2007;75(6 Suppl):S16-S30. doi:10.1016/j.contraception.2007.01.020
  8. Arnal N, de Alaniz MJ, Marra CA. Alterations in copper homeostasis and oxidative stress biomarkers in women using the intrauterine device TCu380A. Toxicol Lett. 2010;192(3):373-378. doi:10.1016/j.toxlet.2009.11.012
  9. Anjalika, Gupta I, Gupta SK, Ganguly NK. Reactive oxygen intermediates and reactive nitrogen intermediates in copper intrauterine device users. Contraception. 1999;59(1):67-70. doi:10.1016/s0010-7824(98)00143-7
  10. Grillo CA, Reigosa MA, de Mele MA. Does over-exposure to copper ions released from metallic copper induce cytotoxic and genotoxic effects on mammalian cells?. Contraception. 2010;81(4):343-349. doi:10.1016/j.contraception.2009.12.003
  11. Beltran-Garcia MJ, Espinosa A, Herrera N, Perez-Zapata AJ, Beltran-Garcia C, Ogura T. Formation of copper oxychloride and reactive oxygen species as causes of uterine injury during copper oxidation of Cu-IUD. Contraception. 2000;61(2):99-103. doi:10.1016/s0010-7824(00)00085-8

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