On this page:
- Key Points
- Scientific Evidence
- Side Effects and Risks
- If You Are Thinking About Using Colloidal Silver
- Key References
- For More Information
Alert from the FDA
The U.S. Food and Drug Administration (FDA) does not consider colloidal silver to be safe or effective for treating any disease or condition and has issued an advisory regarding its safety. Colloidal silver can cause serious side effects, such as argyria.
Colloidal silver consists of tiny silver particles suspended in liquid. Scientific evidence does not support the use of colloidal silver to treat any disease, and serious, irreversible side effects can result from its use.
Colloidal silver products are often marketed as dietary supplements with various unproven health-related claims. This fact sheet provides a general overview of colloidal silver and suggests sources for additional information.
- Colloidal silver is not safe or effective for treating any disease or condition.
- Colloidal silver can cause serious side effects. The most common is argyria, a bluish-gray discoloration of the skin, which is usually not treatable or reversible.
- The FDA and the Federal Trade Commission have taken action against a number of companies (including some companies that sell products over the Internet) for making drug-like claims about colloidal silver products.
- Tell all your health care providers about any complementary health practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Silver is a metallic element. People are exposed to silver, usually in tiny amounts, through air, water, and food, and in certain activities such as jewelry-making, soldering, or developing film.
In 1999, the FDA prohibited the sale of over-the-counter drugs containing colloidal silver or silver salts because they had not been shown to be safe and effective. However, colloidal silver products are still being sold as dietary supplements or homeopathic remedies. Consumers should be aware that unlike some homeopathic remedies, which are often so diluted that none of the original substance is present, some colloidal silver products marketed as homeopathic may not be extremely diluted.
A few prescription drugs containing silver are still in use; for example, silver sulfadiazine is a cream that is applied to burns. However, of the few prescription drugs containing silver, all are for topical use; there are no FDA-approved prescription or over-the-counter drugs containing silver that are taken orally.
Reviews of the scientific literature on colloidal silver have concluded that:
- Silver has no known function in the body.
- Silver is not a nutritionally essential mineral or a cure-all and should not be promoted as such.
- Claims that there can be a “deficiency” of silver in the body and that such a deficiency can lead to disease are unfounded.
- Claims made about the effectiveness of colloidal silver for numerous diseases are unsupported scientifically.
- Colloidal silver can have serious side effects.
Side Effects and Risks
Silver builds up in the tissues of the body. This buildup of silver can lead to a side effect called argyria, a grayish or bluish discoloration of the skin, conjunctiva (the clear membrane that covers the white part of the eye), nails, and gums. In 2009, the FDA issued a warning to consumers about the risk of argyria associated with the use of dietary supplements containing silver, including colloidal silver.
Argyria is usually permanent and may discolor large portions of the body, especially those exposed to the sun. Attempts to reverse the discoloration have usually been unsuccessful, except in instances where only small areas of skin needed to be treated. Argyria has occurred in people who drank homemade colloidal silver liquids as well as in people who used commercial colloidal silver products.
Although argyria is the most common adverse effect of consuming colloidal silver, some cases have been reported where colloidal silver may have caused kidney, liver, or nervous system problems. Colloidal silver may interfere with the body’s absorption of some drugs, such as certain antibiotics, thyroxine (used to treat thyroid disorders), and penicillamine (used to treat conditions such as rheumatoid arthritis and metal poisoning).
If You Are Thinking About Using Colloidal Silver
- There is no scientific evidence for effectiveness and a severe risk for serious side effects from colloidal silver.
- The FDA does not consider colloidal silver to be safe or effective for treating any disease or condition and has issued an advisory regarding its safety.
- Complementary products or practices that have not been proven safe and effective, such as colloidal silver, should never be used as a replacement for conventional medical care or as a reason to postpone seeing a health care provider about a medical problem.
- Tell all your health care providers about any complementary health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care. For tips about talking with your health care providers about complementary health approaches, see NCCAM’s Time to Talk campaign.
For More Information
The NCCAM Clearinghouse provides information on NCCAM and complementary health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.
U.S. Food and Drug Administration (FDA)
The FDA oversees the safety of many products, such as foods, medicines, dietary supplements, medical devices, and cosmetics. Its series of consumer updates includes the publication FDA 101: Dietary Supplements.
Center for Food Safety and Applied Nutrition (CFSAN)
Part of the FDA, CFSAN oversees the safety and labeling of supplements, foods, and cosmetics. It provides information on dietary supplements. Online resources for consumers include Tips for Dietary Supplement Users: Making Informed Decisions and Evaluating Information.
MedWatch, the FDA's safety information and adverse event reporting program, allows consumers and health care providers to file reports on serious problems suspected with dietary supplements.
To report adverse events: 1-800-332-1088 or online at www.accessdata.fda.gov/scripts/medwatch
Federal Trade Commission (FTC)
The FTC is the Federal agency charged with protecting the public against unfair and deceptive business practices. A key area of its work is the regulation of advertising (except for prescription drugs and medical devices).
A service of the National Library of Medicine (NLM), PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals.
- 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.
- 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.
- Chang ALS, Khosravi V, Egbert B. A case of argyria after colloidal silver ingestion. Journal of Cutaneous Pathology. 2006;33(12):809–811.
- 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 http://www.fda.gov/food/recallsoutbreaksemergencies/safetyalertsadvisories/ucm184087.htm on January 18, 2012.
- Fung MC, Bowen DL. Silver products for medical indications: risk-benefit assessment. Clinical Toxicology. 1996;34(1):119–126.
- Gulbranson SH, Hud JA, Hansen RC. Argyria following the use of dietary supplements containing colloidal silver protein. Cutis. 2000;66(5):373–374.
- 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.
- Wadhera A, Fung M. Systemic argyria associated with ingestion of colloidal silver. Dermatology Online Journal. 2005;11(1):12.
- 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.
NCCAM thanks the following people for their technical expertise and review of the content update of this publication: Wendy Weber, N.D., Ph.D., M.P.H., and John (Jack) Killen, Jr., M.D., NCCAM.
This publication is not copyrighted and is in the public domain. Duplication is encouraged.