Each year, Americans shell out almost $3 billion on homeopathic products — and that number is rising.

In the 2007 National Health Interview Survey conducted by the Centers for Disease Control and Prevention (CDC), researchers found that more than 38 percent of all adults and 11 percent of children use alternative medicine as a form of medical treatment. This includes chiropractic treatment, massage therapy, acupuncture, herbal remedies and homeopathy (4 percent of the surveyed population).

What is homeopathy?

The term "homeopathy" is derived from the Greek words "homeo-," meaning similar, and "-pathos," meaning suffering or disease.

Homeopathy was introduced in the late 1700s by a German physician named Samuel Hahnemann and is intended to treat physical and emotional symptoms, to produce lifestyle changes and to improve nutritional status.

How is homeopathy said to work?

Hahnemann formulated the "Law of Similars" which theorizes that "like cures like." This law claims that a substance that produces a set of symptoms in a healthy person has the ability to cure an ill person who has those same symptoms if it is administered at low doses. The administration of a homeopathic remedy allegedly causes the body to react to the worsening of symptoms induced by the remedy, thus promoting a cure. For example, if a given agent appears to cause a runny nose, that same agent might be effective in treating a runny nose if administered at low doses.