Is there any legitimate reason for taking the dietary supplement? The short answer is no, and there may be some serious and strange side effects, reports the August 2007 issue of the Harvard Health Letter.

Silver has several uses in conventional medicine. Silver sulfadiazine is used to treat serious burns. Fabric impregnated with silver is sometimes used as a dressing for wounds or skin infections. And silver nitrate is occasionally used to treat warts and corns.

But there's no proof that taking colloidal silver by mouth has any benefits. As for harm, brain and nerve damage from silver exposure is rare, but colloidal silver can cause kidney damage, stomach distress, and headaches.

The most common problem associated with silver exposure is argyria: The skin turns a bluish gray as granules of silver accumulate in the body. The conjunctiva (the membrane that covers the eyes) and internal organs may also be affected. Once silver is deposited, there's no way to get it out, so the discoloration may be permanent.

Will the colloidal silver products currently on the market turn you blue? The Harvard Health Letter says if you use them for a short time and in recommended amounts, probably not. But some people overdo it. For example, a 59-year-old man was sent to the emergency room because he looked cyanotic ”the bluish color that indicates you're not getting enough oxygen. It turned out he'd been taking a homemade version of colloidal silver whenever he felt a cold coming on.

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Supplemental Information

2. For what health purposes are colloidal silver products marketed?

Colloidal silver products are often marketed with various unproven health-related claims. Examples include that they benefit the immune system; kill disease-causing agents such as bacteria, viruses, and fungi; are an alternative to prescription antibiotics; or treat diseases such as cancer, HIV/AIDS, tuberculosis, syphilis, scarlet fever, shingles, herpes, pneumonia, and prostatitis (inflammation of the prostate).

3. Do colloidal silver products work?

Reviews in the scientific literature on colloidal silver products have concluded that2-5:

Silver has no known function in the body. Silver is not an essential mineral supplement 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 products for numerous diseases are unsupported scientifically. Colloidal silver products can have serious side effects (discussed further below). Laboratory analysis has shown that the amounts of silver in supplements vary greatly, which can pose risks to the consumer.

4. What are the risks of using these products?

Animal studies have shown that silver builds up in the tissues of the body. In humans, buildup of silver from colloidal silver can lead to a side effect called argyria. It causes a bluish-gray discoloration of the skin, other organs, deep tissues, nails, and gums. Argyria cannot be treated or reversed, and it is permanent. While it is not known how argyria occurs, it is thought that silver combines with protein, forming complexes that deposit in the skin and are processed by sunlight (as in traditional photography).6,7 Other side effects from using colloidal silver products may include neurologic problems (such as seizures), kidney damage, stomach distress, headaches, fatigue, and skin irritation. Colloidal silver may interfere with the body's absorption of the following drugs: penacillamine, quinolones, tetracyclines, and thyroxine.5

5. Does the Government regulate dietary supplements containing colloidal silver?

Yes, the Government regulates them, but differently than drugs. The Dietary Supplement Health and Education Act of 1994 places dietary supplements in a special category of foods. This category is regulated differently than other foods and than drugs. For example, manufacturers of dietary supplements, unlike manufacturers of drugs, do not have to prove their product's safety and effectiveness to the FDA before it is marketed. If the product is found to be unsafe after it is marketed, the FDA can take certain actions, such as removing it from the marketplace. The FDA issued a ruling in 1999 that no products containing colloidal silver are generally recognized as safe and effective. The FDA and the Federal Trade Commission (FTC) have sent warning letters to the operators of many Web sites that market colloidal silver with drug-like claims (i.e., that their product diagnoses, treats, cures, or prevents disease).

6. What should people do who are considering or using colloidal silver?

Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care. This is especially important if you are pregnant, nursing a baby, or considering treating a child.

References

Agency for Toxic Substances and Disease Registry. ToxFAQs for Silver. Agency for Toxic Substances and Disease Registry Web site. Accessed at atsdr.cdc/tfacts146.html on December 11, 2006 Fung MC, Bowen DL. Silver products for medical indications: risk-benefit assessment. Journal of Toxicology. 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. FDA bans colloidal silver products, cites lack of data. FDA Consumer. 1999;33(6). Accessed at fda/fdac/departs/1999/699_upd.html December 11, 2006. Natural Medicines Comprehensive Database. Colloidal silver. Natural Medicines Comprehensive Database Web site. Accessed on December 11, 2006. 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. Hori K, Martin TG, Rainey P, et al. Believe it or not--silver still poisons! Veterinary and Human Toxicology. 2002;44(5):291-292.