Over fifty years ago, a chemical called ethylene diamine tetra-acetic acid—better known as EDTA—received approval from the U.S. Food and Drug Administration to treat lead poisoning. While still used for this purpose, EDTA and drugs similar to it are now also being prescribed to treat a wide variety of conditions ranging from coronary artery disease to arthritis.
Although EDTA is not approved for treating problems other than heavy lead poisoning, it’s perfectly legal for doctors to treat patients with it in any way they deem appropriate. Prescribing a drug for an indication that has not been approved by the FDA is known as “off-label” usage, and it’s far more common than many people realize.
According to the National Center for Complementary and Alternative Medicine, in just one year, over 110,000 patient visits were made for chelation therapy in the United States. Most of these treatments are thought to be for unapproved uses.
Among the most common off-label uses of EDTA is the treatment of alleged “low-level” heavy metal toxicity. EDTA speeds the elimination of metals—not just lead—from the body by attaching, or “chelating”, to them. (The bound metal can then be rapidly excreted in the urine.) Mercury, arsenic, and aluminum, for example, all bind to EDTA.
Most physicians test for levels of these metals only when there is reason to believe that exposure to a specific heavy metal has occurred or when an individual is experiencing symptoms that are clearly suggestive of toxicity. However, some clinicians utilize these tests more liberally. Some use them to evaluate nonspecific symptoms like headache, chronic fatigue, bone pain, and “brain fog”; others simply order them on every patient they see.
Hair, urine and blood tests are used to measure heavy metal levels; even nail clippings and saliva are sometimes utilized. “Provocative” testing with EDTA is performed by some clinicians; this type of testing involves challenging patients with a chelating treatment and then measuring the amount of metal eliminated in the urine.
When levels of heavy metals are found to be “elevated”, EDTA chelation therapy may be recommended to help “detoxify” the body. EDTA therapy consists of repeated, intravenous infusions several times each week for a month or more. Some patients continue with lifelong therapy. Costs often run in the thousands of dollars and are generally paid out-of-pocket by patients because the therapy is not covered by insurance.
Critics raise several concerns about this approach. They argue that hair, saliva, and nail tests are not accurate measures of heavy metal toxicity, and even elevated blood and urine tests are frequently misinterpreted. Mercury levels, for example, can be transiently high simply from eating seafood; when that is the case, they’ll often return to “normal” within several days.
Also, levels considered by some clinicians to be toxic are thought to be normal by others. Virtually everyone contains detectable levels of heavy metals in their bodies—after all, many of them are present in the food we eat, the water we drink, and the air we breathe. However, there presence doesn’t necessarily indicate poisoning; at low levels, many heavy metals produce no untoward health effects.
Finally, there is virtually no scientific evidence to suggest that chelation treatment for low-level heavy metal toxicity produces any significant benefits. For people who have low levels of lead or any other heavy metal in their blood, taking EDTA is unlikely to make a difference. Although there are a lot of doctors out there that will offer chelation for presumed low-level heavy metal toxicity, there’s very little scientific evidence to support it being used this way.
For individuals concerned about heavy metals in their bodies, there’s a simpler approach than chelation therapy. Except in severe cases of poisoning, simply limiting exposure to heavy metals is perhaps the best way to bring levels down.
Chelation Therapy (American Cancer Society)
Chelation Therapy (American Heart Association)