Two kilo bars of silver.

Colloidal silver, which is mostly microscopic bits of silver floating in some form of liquid, has been used medically for decades. But does it really work? © Donall O Cleirigh

When Dr. G.L. Rohdenburg published an article in 1915 on the benefits of colloidal silver in treating tumors, he likely had no idea that this product would have such staying power. Nearly 100 years later, colloidal silver is used by some as a dietary supplement, decongestant and a treatment for all kinds of ailments and illnesses.

Although colloidal silver has been called a cure-all, its healing properties, as reported by the companies that manufacture the supplement and its related products, haven't been published in reputable medical journals [source: Zeratzky]. It's really not known if colloidal silver cures ailments, and the side effects include everything from seizures and kidney damage to fatigue and skin irritation.

So what is this mysterious metal, and what does it do? Is it even a real metal, and how well does it work? And should people be concerned about the side effects?

First things first: yes, colloidal silver really is silver, or at least, a silver residue of sorts. A colloid is a particle of some substance, broken down and mixed into or suspended in liquid [source: Merriam-Webster Online]. Colloidal silver is mostly microscopic bits of silver floating in water or some other gelatinous goo.

Silver is naturally found in food and water, and when recommended by a physician, the typical dosage of colloidal silver is about one teaspoon. Due to the lengthy list of side effects and relatively sparse information on what this product can actually do for you, you won't find many health experts promoting the substance.

Read on to learn about the alleged benefits of colloidal silver.