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Colloidal silver

Colloidal silver consists of tiny particles of silver suspended in a liquid. Scientific research does not support the use of colloidal silver to treat disease and irreversible side effects may result from its use. Colloidal silver products are often marketed as nutritional supplements with various unproven claims of health benefits.

Key points

  • Colloidal silver is not safe or effective for the treatment of any disease or condition.
  • Colloidal silver can cause serious side effects. The most common of these is argyria, a bluish-gray discoloration of the skin that is usually not treatable or reversible.

Background

Silver is a metallic element. Humans are exposed to silver in minimal amounts through air, water and food, as well as during certain activities such as jewelry making, soldering and film developing. In America, the sale of supplements containing colloidal silver or silver salts was already banned in 1999, as the safety and harmlessness of these substances has not been proven. However, products containing colloidal silver continue to be sold in many countries as nutritional supplements or homeopathic preparations. One should be aware that some products sold as homeopathic colloidal silver preparations, unlike other homeopathic preparations which are highly diluted, are not extremely diluted and therefore contain a relatively high proportion of colloidal silver. There are still some prescription products that contain silver. One example is silver sulfadiazine, a cream that is applied to the skin for burns. However, all prescription silver products are intended for application to the skin and not for oral ingestion.

Scientific facts

A review of the scientific literature comes to the following conclusions:

  • Silver has no known function in the body.
  • Silver is not a nutritionally essential mineral and should not be marketed as such.
  • Claims that there can be a deficiency of silver in the body and that such a deficiency can lead to disease are without any scientific basis.
  • Claims regarding the effectiveness of colloidal silver for numerous conditions are not scientifically supported.
  • Colloidal silver can have serious side effects.

Side effects and risks

Silver accumulates in body tissue. This accumulation of silver can lead to a side effect called argyria, which is characterized by a grayish or bluish discoloration of the skin, eyes, nails and gums. Argyria is usually more permanent in nature and can affect large areas of the body, particularly skin areas exposed to the sun. Attempts to remove these discolorations are usually unsuccessful, except in cases where only small areas of skin need to be treated. Argyria has occurred both in people who have drunk homemade colloidal silver preparations and in people who have used commercial colloidal silver products. Although argyria is the most common side effect of consuming colloidal silver, there are some reported cases where colloidal silver has caused kidney, liver or nervous system problems. Colloidal silver can affect the body's absorption of certain medications, which include certain antibiotics, thyroxine and penicillamine (used to treat rheumatoid arthritis and heavy metal poisoning).

References

  1. Agency for Toxic Substances and Disease Registry.ToxFAQs for Silver. Agency for Toxic Substances and Disease Registry Web site. Accessed at www.atsdr.cdc.gov/toxfaqs/tf.asp?id=538&tid=97 on January 18, 2012.
  2. Brandt D, Park B, Hoang M, et al. Argyria secondary to ingestion of homemade silver solution.Journal of the American Academy of Dermatology. 2005;53(2 suppl 1):S105-107.
  3. Chang ALS, Khosravi V, Egbert B. A case of argyria after colloidal silver ingestion.Journal of Cutaneous Pathology. 2006;33(12):809-811.
  4. Consumer advisory: dietary supplements containing silver may cause permanent discoloration of skin and mucous membranes (argyria). U.S. Food and Drug Administration Web site. Accessed at www.fda.gov/Food/DietarySupplements/Alerts/ucm184087.htm on January 18, 2012.
  5. Fung MC, Bowen DL. Silver products for medical indications: risk-benefit assessment.Clinical Toxicology. 1996;34(1):119-126.
  6. Gulbranson SH, Hud JA, Hansen RC. Argyria following the use of dietary supplements containing colloidal silver protein.Cutis. 2000;66(5):373-374.
  7. U.S. Food and Drug Administration. Rules and regulations: over-the-counter drug products containing colloidal silver ingredients or silver salts. Final rule.Federal Register. 1999;64(158):44653–44658.
  8. Wadhera A, Fung M. Systemic argyria associated with ingestion of colloidal silver.Dermatology Online Journal. 2005;11(1):12.
  9. White JM, Powell AM, Brady K, et al. Severe generalized argyria secondary to ingestion of colloidal silver protein.Clinical and Experimental Dermatology. 2003;28(3):254-256.