Colloidal silver is a popular alternative therapy.

Its advocates claim that it’s an effective treatment for all sorts of infections and diseases, ranging from the common cold to cancer.

However, the use of colloidal silver is controversial and has been linked to serious side effects.

Two Dropper Bottles

Colloidal silver is the term used to describe tiny particles of silver suspended in a liquid.

Given their small size, a normal filtering process would not remove them.

The size of the silver particles in colloidal silver can vary, but some are so tiny that they are referred to as “nanoparticles.” This means that they are less than 100 nm in size and invisible to the naked eye (1).

Before modern antibiotics were developed, colloidal silver was used as an all-purpose remedy for various infections and illnesses.

Recently, it has experienced a revival in popularity, with some claiming it can replace antibiotics or other medical therapies to treat bacterial, viral and fungal infections.

A smaller number of people also claim it can help treat illnesses such as Lyme disease, tuberculosis and even HIV/AIDs.

Those who use colloidal silver take it as a dietary supplement or apply it directly to their skin.

The solution can be found in various strengths, depending on how much silver it contains.

Summary Colloidal silver is a suspension of silver particles in a liquid. It’s an ancient remedy that was once used to treat bacterial, viral and fungal infections.

Colloidal silver is said to have broad antibacterial and antiseptic effects when taken orally or placed on a wound.

It’s unknown exactly how colloidal silver works. However, research suggests that it attaches to proteins on the cell walls of bacteria, damaging their cell membranes (2, 3, 4).

This allows silver ions to pass into the cells, where they can interfere with the bacteria’s metabolic processes and damage its DNA, leading to the cell’s death.

It’s thought that the effects of colloidal silver vary depending on the size and shape of the particles of silver, as well as their concentration in a solution (5, 6).

A large number of small particles has a greater surface area than a lower number of large particles. As a result, a solution that contains more silver nanoparticles, which have a smaller particle size, may release more silver ions.

Silver ions are released from the silver particles when they come into contact with moisture, such as body fluids.

They are considered to be the “biologically active” part of colloidal silver that gives it its medicinal properties (4, 7, 8).

However, it’s worth noting that colloidal silver products are not standardized and may have serious side effects.

Commercially available colloidal solutions can vary widely in the way that they are produced, as well as the number and size of the silver particles they contain.

Summary The exact way colloidal silver works is not fully understood. However, it’s thought that silver can bind to bacterial cells and damage their cell walls and DNA, resulting in cell death.

Some people claim that colloidal silver can help treat bacterial, viral and fungal infections.

Antibacterial

Before the discovery of antibiotics, colloidal silver was a popular antibacterial treatment.

Test-tube studies have shown that colloidal silver can kill a wide range of bacteria (8, 9, 10).

This has translated to its use in some healthcare products like wound creams, wound dressings and medical equipment (7, 11).

However, due to the risks associated with ingesting colloidal silver, the effects of doing so have not been tested as an antibacterial treatment in humans (12).

Antiviral

Proponents of colloidal silver also claim that it can have antiviral effects in your body.

Some studies have suggested that different types of silver nanoparticles may help kill viral compounds (13).

However, the amount of nanoparticles in a colloid solution can vary, and a recent study found colloidal silver to be ineffective at killing viruses, even in test-tube conditions (9).

No studies have investigated the effects of ingesting colloidal silver on viruses in people, so it lacks evidence to support its use in this way.

Antifungal

Colloidal silver is also said to be capable of treating fungal infections.

One test-tube study showed it may stop the growth of some strains of fungi (14).

However, many things can kill fungi in a lab, and this doesn't mean that colloidal silver can treat fungal infections in humans.

At the moment, there is little evidence to support the claim that colloidal silver is a reliable topical antifungal agent.

Additionally, no studies have investigated the effects of ingesting colloidal silver on fungal infections in humans.

Summary Colloidal silver is claimed to have antibacterial, antiviral and antifungal properties. However, there is currently no evidence that colloidal silver has any of these health benefits.

You’re environmentally exposed to extremely small amounts of silver every day (15).

It’s present in very tiny amounts in drinking water, the food supply and even the air you breathe.

As a compound, the silver found in the environment is thought to be quite safe.

However, the environmental and health risks of silver nanoparticles are not well understood, and ingesting colloidal silver is considered unsafe.

The biggest risk associated with chronic exposure to colloidal silver is argyria.

Argyria is a condition that turns the skin a blue-gray color due to a buildup of silver metal particles in the body and skin. Silver deposits can also occur in the intestines, liver, kidneys and other organs (16).

You are most at risk of developing argyria if you’re taking a silver-containing food supplement or work in a job that exposes you to large amounts of silver.

It’s thought that to develop argyria, you would have had to ingest silver compounds over a long period of time. However, the exact amounts and time frame that would put you at risk aren’t known (16).

The real risks of ingesting nanoparticles, which may be present in colloidal silver products, are also unknown.

However, given that these particles may more easily pass into your cells and possibly cross the blood-brain barrier, they are considered a probable health risk (6).

Applying colloidal silver to your skin is considered less risky than ingesting it. However, if the solution contains very small nanoparticles, you may absorb these through your skin (17).

What’s more, if you use it frequently on an open wound, you may experience localized argyria due to a buildup of silver in the surrounding tissue (18).

There is also the potential for silver allergy, although this is considered rare (7).

Summary Ingesting colloidal silver puts you at risk of developing a condition called argyria. Ingesting silver nanoparticles, which may be present in colloidal silver solutions, is also considered to be risky.

Colloidal silver products can vary widely in their composition, so their effects may also vary widely.

Additionally, silver has no function in your body and no known benefits when taken orally.

Considering the risks and lack of proven benefits, using colloidal silver products is probably not a good idea.