1. health and fitness

Colloidal Silver
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.
Key Points
National Institutes of Health
National Center for Complementary
and Alternative Medicine
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 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.
© Ryan McVay/Photodisc/Thinkstock
U.S. DEPARTMENT OF HEALTH
AND HUMAN SERVICES
Alert from the FDA
Background
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.
Scientific Evidence
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).
2
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 at
nccam.nih.gov/timetotalk.
Selected References
Agency for Toxic Substances and Disease Registry. ToxFAQs for Silver. Agency for Toxic Substances and Disease Registry
Web site. Accessed at http://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.
3
For More Information
NCCAM Clearinghouse
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.
Toll-free in the U.S.: 1-888-644-6226
TTY (for deaf and hard-of-hearing callers): 1-866-464-3615
Web site: nccam.nih.gov
E-mail: [email protected]
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.
Web site: www.fda.gov
Toll-free in the U.S.: 1-888-463-6332
Center for Food Safety and Applied Nutrition (CFSAN)
Part of the FDA, CFSAN oversees the safety and labeling of supplements, foods, and
cosmetics. It has information on dietary supplements. Online resources for
consumers include Tips for Dietary Supplement Users: Making Informed Decisions and
Evaluating Information.
Web site: www.fda.gov/AboutFDA/CentersOffices/OfficeofFoods/CFSAN/
Toll-free in the U.S.: 1-888-723-3366
The FDA’s MedWatch
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.
Web site: www.fda.gov/Safety/MedWatch/HowToReport/ucm053074.htm
Toll-free in the U.S.: 1-888-463-6332
To report adverse events: 1-800-332-1088 or online at
www.accessdata.fda.gov/scripts/medwatch
4
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).
Web site: www.ftc.gov
Toll-free in the U.S.: 1-877-382-4357
PubMed®
A service of the National Library of Medicine, PubMed contains publication information and (in
most cases) brief summaries of articles from scientific and medical journals.
Web site: www.ncbi.nlm.nih.gov/sites/entrez
Acknowledgements
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.
NCCAM has provided this material for your information. It is not intended to substitute for the
medical expertise and advice of your primary health care provider. We encourage you to
discuss any decisions about treatment or care with your health care provider. The mention of
any product, service, or therapy is not an endorsement by NCCAM.
National Institutes of Health
♦♦♦
U.S. Department of Health and Human Services
5
D209
Created May 2004
Updated March 2013