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Other common name(s): none

Scientific/medical name(s): Mo, sodium molybdate, ammonium molybdate


Molybdenum is an element that is present in very small amounts in the body. It is involved in many important biological processes, possibly including development of the nervous system, waste processing in the kidneys, and energy production in cells.


Molybdenum is an essential element in human nutrition, but its precise function and interactions with other chemicals in the body are not well understood. Some evidence suggests that too little molybdenum in the diet may be responsible for some health problems. Molybdenum is used to treat rare inherited metabolic diseases, such as Wilson's disease in which the body cannot process copper. More research is needed to learn whether it may have a role in preventing cancer and other diseases. It has shown promise in animal studies in reducing the harmful effects of certain cancer drugs on the heart and lungs.

How is it promoted for use?

Proponents claim molybdenum is an antioxidant that prevents cancer by protecting cells from free radicals, destructive molecules that may damage cells. Some supporters also claim that molybdenum prevents anemia, gout, dental cavities, and sexual impotence.

What does it involve?

Food is the major source of molybdenum for most people. Common sources of molybdenum include legumes, such as beans, peas, and lentils; grains; leafy vegetables; liver; and nuts. However, the amount of molybdenum in plants varies according to the amount in the soil.

Humans require very small amounts of molybdenum, and deficiency appears to happen only under the rarest of circumstances. For example, molybdenum deficiency may appear in a person fed entirely through the veins for a very long time, or in a person with a genetic problem in which the body cannot use the molybdenum that is eaten in foods.

Molybdenum is sold as a supplement in some health food stores and over the Internet. It is sold as sodium molybdate or ammonium molybdate in capsule form, usually combined with other nutrients. A typical dosage is 75 micrograms (µg or mcg) daily.

What is the history behind it?

Knowledge of molybdenum dates back to the Middle Ages. Pure molybdenum was first produced in 1893. Serious research into molybdenum's importance in the human body began only within the past few decades. In 2001, the U.S. Food and Nutrition Board established the recommended dietary allowance, or RDA, of molybdenum for most adults at 45 micrograms, with an RDA of 50 micrograms for women who are pregnant or breast-feeding.

What is the evidence?

A large, randomized study was conducted in Linxian, an area of north central China whose residents have very high rates of esophageal and stomach cancers. Researchers gave more than 30,000 people one of several combinations of essential minerals and nutrients. One group received vitamin C and molybdenum. The scientists did not find any reductions in cancer mortality rates among those who received molybdenum. Some evidence suggested that the soil in Linxian, which contained low levels of molybdenum, may have led to the formation of chemicals in plants that increase the risk of cancers of the esophagus. More data is needed to find out whether there is a connection. A follow up study showed that there were fewer deaths from stroke in people who had gotten the vitamin C and molybdenum up to 10 years earlier. No effect on cancer was seen from this supplement.

Tetrathiomolybdate (a form of molybdenum that is different from the forms used in dietary supplements) is being tested as a cancer treatment. It is known that molybdenum depletes copper in the body, and copper is required for new blood vessels to be formed. This would mean that new tissues, including cancerous tumors, would not be able to grow. Some studies in mice show that tetrathiomolybdate might improve the response to breast cancer drugs, but human studies are required to find out whether this is true. Animal studies also suggest that tetrathiomolybdate might be helpful in reducing the heart and lung damage caused by some chemotherapy drugs. This possibility has not yet been studied in human clinical trials.

In 2003, researchers did a small study on people with advanced kidney cancer. Researchers gave tetrathiomolybdate (a form of molybdenum) to 15 patients to reduce the copper levels in their bodies. Even though no one had their cancer go away, 4 people's tumors stopped growing for 6 months. But some patients had anemia (low red blood cell counts) or low white blood cell counts due to the lack of copper and had to have their molybdenum doses reduced. The researchers noted that this approach might be useful if used along with other cancer treatments. They recommended large, well-controlled studies to look at tetrathiomolybdate more closely. However, a small 2006 study did not show a reduction in growth of advanced prostate cancer.

A study published in 2008 looked at people with malignant mesothelioma, testing tetrathiomolybdate as a follow-up treatment after surgery to remove the cancer. This very small study showed some survival improvement in people with stage 1 or 2 mesothelioma, but did not help those with later stage cancer. More study of tetrathiomolybdate along with standard mesothelioma treatment is needed to help confirm whether it can help others.

Are there any possible problems or complications?

This product is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must be tested before being sold), the companies that make supplements are not required to prove to the Food and Drug Administration that their supplements are safe or effective, as long as they don't claim the supplements can prevent, treat, or cure any specific disease.
Some such products may not contain the amount of the herb or substance that is on the label, and some may include other substances (contaminants). Actual amounts per dose may vary between brands or even between different batches of the same brand. In 2007, the FDA wrote new rules to improve the quality of manufacturing for dietary supplements and the proper listing of supplement ingredients. But these rules do not address the safety of the ingredients or their effects on health.
Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements. Even though some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.

In animals, molybdenum deficiency has not been seen naturally, and must be produced by a carefully controlled diet. Overdoses are extremely rare. Large amounts of molybdenum produce symptoms of copper deficiency in cattle, and taking too much supplemental molybdenum could produce the same symptoms in humans. Symptoms of too much molybdenum include tiredness, dizziness, rashes, low white blood cell counts, and anemia. High molybdenum levels are also linked to gout.

In workplaces where it is processed, inhaling molybdenum dust can irritate the nose and throat and may cause coughing and wheezing. In workplace settings, prolonged exposure to high molybdenum levels has been linked to weakness, fatigue, headache, poor appetite, and muscle and joint pain.

Molybdenum deficiencies are very rare among humans; therefore most practitioners do not recommend supplements.

Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.

Additional resources

More information from your American Cancer Society

The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our Web site (www.cancer.org) or ordered from our toll-free number (1-800-227-2345).

Dietary Supplements: What Is Safe?

Complementary and Alternative Methods and Cancer

Placebo Effect

Learning About New Ways to Treat Cancer

Learning About New Ways to Prevent Cancer

The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management


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Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.

Last Medical Review: 10/21/2010
Last Revised: 04/19/2011