People are commonly exposed to silver, usually in tiny
amounts, through the environment (such as the air), drinking water,
and food, and possibly their work or hobbies.1 Silver has no known
biological function in living organisms.
Silver has had some medicinal uses going back for centuries.
However, more modern and less toxic drugs have eliminated most of
those uses. A few prescription drugs containing silver are still
available. For example, silver nitrate can be used to prevent an eye
condition called conjunctivitis in newborn babies and to treat
certain skin conditions, such as corns and warts. Another drug,
silver sulfadizine, can be used to treat burns. These drugs are
applied to the body (i.e., they are not taken internally), and they
can have negative side effects.
Colloidal silver products consist of tiny silver particles suspended
in a liquid base. Sometimes other ingredients are added, such as
proteins, coloring, etc. The products are usually taken by mouth (in
which case the products are considered dietary supplements; see the
text box below). Some other types are sprayed, applied to the skin,
or injected into a vein.
For what health purposes are colloidal silver products
marketed?
Colloidal silver products are often marketed with various
unproven health-related claims. Examples include that they benefit
the immune system; kill disease-causing agents such as bacteria,
viruses, and fungi; are an alternative to prescription antibiotics;
or treat diseases such as cancer, HIV/AIDS, tuberculosis, syphilis,
scarlet fever, shingles, herpes, pneumonia, and prostatitis
(inflammation of the prostate).
Do colloidal silver products work?
Reviews in the scientific literature on colloidal silver products
have concluded that:
- Silver has no known function in the body.
- Silver is not an essential mineral supplement or a cure-all and
should not be promoted as such.
- Claims that there can be a "deficiency" of silver in the body and
that such a deficiency can lead to disease are unfounded.
- Claims made about the effectiveness of colloidal silver products
for numerous diseases are unsupported scientifically.
- Colloidal silver products can have serious side effects (discussed
further below).
- Laboratory analysis has shown that the amounts of silver in
supplements vary greatly, which can pose risks to the consumer.
What are the risks of using these products?
Animal studies have shown that silver builds up in the tissues
of the body. In humans, buildup of silver from colloidal silver can
lead to a side effect called argyria. It causes a bluish-gray
discoloration of the skin, other organs, deep tissues, nails, and
gums. Argyria cannot be treated or reversed, and it is permanent.
While it is not known how argyria occurs, it is thought that silver
combines with protein, forming complexes that deposit in the skin
and are processed by sunlight (as in traditional photography). Other
side effects from using colloidal silver products may include
neurologic problems (such as seizures), kidney damage, stomach
distress, headaches, fatigue, and skin irritation. Colloidal silver
may interfere with the body's absorption of the following drugs:
penacillamine, quinolones, tetracyclines, and thyroxine.
What should people do who are considering or using colloidal
silver?
Tell your health care providers about any complementary and
alternative practices you use. Give them a full picture of what you
do to manage your health. This will help ensure coordinated and safe
care. This is especially important if you are pregnant, nursing a
baby, or considering treating a child. |
