Ferrum metallicum is commonly known as iron. It is a homeopathic physician's treatment of choice for anemia, rheumatism, headache, and other conditions. During production of this remedy, it is diluted to the point that no measurable amount, not even a molecule, of iron is in the final product. Homeopathic advocates believe that the electromagnetic signature of the original iron is responsible for healing. The effectiveness of this remedy has not yet been determined by any double-blind clinical studies, and there is no scientific evidence that it actually works as claimed.

The iron begins as a dark gray powder. This powder does not dissolve with either water or alcohol. To create the homeopathic remedy ferrum metallicum, it must be mixed with powdered lactose. One part ferrum metallicum is mixed with powdered lactose and then one part of the resulting mixture is combined with more powdered lactose. This is repeated eight times. At 8x titration, the powder will dissolve. The final product is made into small, white pellets or an alcohol-based tincture.

Practitioners of homeopathic medicine use this remedy for those who have pale skin and weakness along with cold hands and feet. These symptoms get worse when the patient sweats, sits still, overheats, and at midnight. Symptoms get better when the patient is walking slowly or stands up. Additional indications that may warrant ferrum metallicum include an anemic condition that stems from a loss of blood, pitting skin when pressure is applied, and trembling. The recommended dosages vary depending on the individual patient.

Ferrum metallicum is recommended when muscles become flabby and relaxed and for rheumatism of the shoulder. A patient with painful hips, tibia, and feet, as well as lumbago, or lower back pain, may also be prescribed this remedy. Complaints of hammering, pulsating, or congestive headaches are still more indications that a patient may need this homeopathic medication. Vertigo, or dizziness, may or may not be present with the headache.

There are no validated research studies that show the effectiveness of ferrum metallicum. All evidence is anecdotal or from a patient's or doctor's own experience. Most conventional physicians dismiss homeopathic medicine. They often attribute any healing as simply the placebo effect.

Although there are no known side effects, people should exercise caution when taking any medication. Those who want to take ferrum metallicum should consult with their doctor first. Pregnant or nursing women, as well as children, should be especially careful because the safety of ferrum metallicum has not been tested on these populations.