Editorial Feature

The Applications of Colloidal Silver

Article updated on 23rd February 2021

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Colloidal silver is a suspension of tiny particles of silver in a liquid, or sometimes gel. The particles are so small that they can’t be filtered out of the solution; these nanoparticles range from one tenth to one thousandth of a micron.

Used as a popular alternative therapy, colloidal silver is believed to have antibacterial and antiseptic effects when taken orally or placed on a wound; it can be bought as a liquid, ointment, and topical or nasal spray. However, its use is controversial and linked to serious side effects.

No one is sure how colloidal silver works, but research suggests that it attaches itself to the proteins on the cell walls of bacteria and damages the cell membrane. Silver ions are then able to pass into the cell where they interfere with the bacteria’s metabolic processes and damage its DNA, which leads to cell death. How ‘effective’ the ‘treatment’ is, likely depends on the size and shape of the nanoparticles, in addition to their concentration.

Popular Antibacterial Treatment

Colloidal silver used to be a popular antibacterial treatment, and today is still found in wound creams, dressings and medical equipment to prevent infection and speed up healing. Test tube studies have shown that it can kill a wide range of bacteria.

Proponents also claim that colloidal silver has antiviral effects in the body, but the number of nanoparticles in a sample varies and recent studies have found that it is ineffective in killing viruses even in test tubes.

It is also claimed that colloidal silver can treat fungal infections. Test tube studies have shown that it may stop the growth of some strains of fungus, but lots of things can kill fungus in the laboratory, meaning that there is insufficient evidence to support the claim that it is a reliable topical antifungal.

Effectiveness of Colloidal Silver

Whilst there is some evidence of silver’s effectiveness, scientists have only conducted experiments on animal or cell cultures in test tubes, not in placebo-controlled studies in humans. Nor has the effects of ingesting colloidal silver been tested, firstly because it is considered a danger to human health, and secondly because companies are not willing to fund research into something they can’t patent (silver is a chemical element and so cannot be patented).

Below is a summary of some of the findings scientists have made:

  • Test tube studies have shown colloidal silver acted as an antibiotic and antifungal against certain strains, suggesting it could be a remedy for athlete’s foot or to disinfect small cuts. It has also been shown to act against antibiotic-resistant microbes.
  • In lab cultures, colloidal silver triggered apoptosis in breast cancer cells through antioxidant activity.
  • Colloidal silver damages the cell walls of cultured bacteria strains such as Salmonella and E. coli.
  • Studies in animals have shown it is effective against smallpox.
  • Colloidal silver can prevent HIV from attaching to host cells.


The environmental and health risks of colloidal silver are poorly understood, but the consensus is that is unsafe to ingest. Furthermore, Government regulatory bodies have issued statements saying it is not an effective treatment for any condition.

Too much silver in a person’s system can cause them to turn blue, a condition known as argyria. Silver particles of dust settle on to the tissues and bind with sulfur using UV light and turns to black silver sulfide, which has a blue appearance on the skin. This build-up of silver in the skin causes the color change, and there are often deposits found in the organs too. It’s not harmful, and the occasional topical use of colloidal silver won’t turn you blue!


Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Kerry Taylor-Smith

Written by

Kerry Taylor-Smith

Kerry has been a freelance writer, editor, and proofreader since 2016, specializing in science and health-related subjects. She has a degree in Natural Sciences at the University of Bath and is based in the UK.


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