IN SHORT: Social media posts claim that colloidal silver has many uses and no adverse side effects when taken orally or topically. This is false, colloidal silver is not safe and should not be ingested.
Many posts doing the rounds on Facebook in South Africa claim that something called colloidal silver has many health benefits.
"It has many uses and no adverse side effects," one of the posts reads.
According to the posts, colloidal silver can treat many illnesses, including pneumonia, skin rashes and sinus infections.
The posts add that colloidal silver can be taken orally or can be used topically, or applied directly to the skin.
These posts have been doing the rounds since 2018. One of them has been posted to a public group with over 2,000 followers.
So what is colloidal silver, and does it have "many uses and no adverse side effects"? We checked.
A liquid mixture with small silver particles
Colloidal silver is a mixture that consists of small silver particles that are suspended in a liquid. It was used to treat infections and wounds before the availability of antibiotics.
A colloid occurs when a microscopic particle, such as silver, is dispersed and suspended through a second substance, in this case the liquid.
The US's National Institutes of Health says colloidal silver has often been marketed as a dietary supplement, but there is no evidence to support this use.
But is it safe to use?
Colloidal silver is not safe, says US drug administration
In a 1999 report on the safety of silver salts, the US's Food and Drug Administration (FDA) deemed colloidal silver unsafe and ineffective:
The Food and Drug Administration (FDA) is issuing a final rule establishing that all over-the-counter (OTC) drug products containing colloidal silver ingredients or silver salts for internal or external use are not generally recognized as safe and effective and are misbranded.
Colloidal silver was declared unsafe after many products containing it had been falsely marketed as treatments for various diseases and conditions.
"FDA is not aware of any substantial scientific evidence that supports the use of OTC colloidal silver ingredients or silver salts for these disease conditions," it said.
Beware of side effects
Sign up for free AllAfrica Newsletters
Get the latest in African news delivered straight to your inbox
Cleveland Clinic, a non-profit academic medical centre in the US, also advises people to never use colloidal silver internally.
The medical centre says ingesting the mixture can lead to poor medication absorption, reducing the effectiveness of certain medications such as antibiotics.
Colloidal silver can also cause toxicity as the silver can interfere with kidney and liver function. In rare cases, high doses of colloidal silver can cause kidney damage and seizures, according to the Mayo Clinic, a research hospital in the US.
Colloidal silver can build up in the body's tissues over months or years, if ingested, which can lead to a condition called argyria, where the skin, eyes, nails and gums take on a blue tint.
"Argyria does not typically cause a major health problem. But it can be a cosmetic concern because it does not go away when you stop taking silver products."
The US-based Memorial Sloan Kettering Cancer Center (MSK) says humans do not need silver to function normally: "Silver actually denatures proteins and can make many enzymes lose their effects."
Enzymes are proteins in our body that help with metabolism and chemical reactions.
Topically, these silver compounds have been used as antiseptics, says MSK, but reported side effects include methemoglobinemia, a blood disorder where too little oxygen is delivered to your cells.
According to Cleveland Clinic, if you want to use colloidal silver mixture topically, it's best to get your doctor's advice first. But the safest of all would be to avoid it entirely.
