Taking colloidal silver by mouth is not thought to be safe or effective for any of the health claims that many manufacturers make. Silver is not an essential mineral, as some sellers of silver products say.

Colloidal silver products are made of tiny silver bits that float in a liquid. This is the same type of precious metal used in jewelry, dental fillings and silverware.

Colloidal silver products are often marketed as dietary supplements to take by mouth. These products also come in forms to use on the skin.

Manufacturers of colloidal silver products often say that their products are cure-alls. Some claim these products can improve your immune system and fight bacteria and viruses. And they say these products can treat cancer, HIV/AIDS, COVID-19, shingles, herpes, acne, eye diseases and prostatitis.

But little research has been done to study these health claims. In fact, the U.S. Food and Drug Administration has acted against some manufacturers of colloidal silver products for making unproven health claims.

It's not clear how much colloidal silver you can take before it may be harmful. But it can build up in your body's tissues over months or years. This can lead to a blue-gray tint on your skin, eyes, organs, nails and gums. This condition is called argyria (ahr-JIR-e-uh). 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.

In rare cases, too many doses of colloidal silver can cause long-lasting severe health problems, such as kidney damage and seizures.

Colloidal silver products also may interact with medicines, such as some antibiotics and levothyroxine (Unithroid, Levoxyl, others).