The Risks of Chelation Therapy for Autism

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Chelation therapy is a process in which potent medications are used to remove heavy metals from the human body. Chelation has been used successfully to treat lead poisoning among other disorders. Starting in the late '90s, chelation was recommended by some alternative practitioners as a tool for curing autism.

The reality is that chelation neither improves nor cures symptoms of autism. In addition, if used incorrectly and outside of a hospital setting, chelating drugs can be quite dangerous.

Female doctor and boy with stethoscope in medical practice
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Standard Uses

Chelation was developed to treat heavy metal poisoning discovered in people who painted naval vessels with lead-based paint. As such, it has been found to be useful for treating poisoning by arsenic, lead, mercury, gold, iron, cadmium, and copper. Some research suggested that chelation could be helpful for cardiovascular disease and cancer, but neither of these uses is supported by research.

Alternative Treatment for Autism

The idea of using chelation as a tool for treating autism grew out of a belief that mercury-containing thimerosal (a preservative) in vaccines was the direct cause of a rapid increase in autism spectrum diagnoses. The theorists reasoned that if mercury was the cause of autism, then removing mercury from the body would cure autism.

The main force behind chelation came from the Autism Research Institute. A group of practitioners working on curing autism developed a set of protocols for a treatment called Defeat Autism Now (DAN!). These protocols were based on the idea that autism is a condition that can be cured through "biomedical" interventions.

However, these theories are not widely accepted in the medical community and have even been found to potentially cause harm. The Defeat Autism Now protocol was discontinued completely for these reasons, among others, in 2011.

The Process

Chelation starts with a provocation test in which the patient is given a chelating drug. A chemical analysis of the patient's urine shows whether unusually high levels of heavy metals are being excreted. On the basis of this test, a practitioner may administer oral or intravenous drugs or even use nasal sprays, suppositories or creams.

All of these treatments have the same function: the medication bonds with the metal ions, making the metals less chemically reactive. The new and less reactive compound becomes water-soluble and is flushed out of the body through the bloodstream.

Chelation, when used appropriately and properly, is administered by a doctor in a medical facility. The process is carefully monitored because it does carry risks. There are many chelating drugs, all of which have significant side effects. The most effective and safe of these includes DMSA (other names are: chemet, dimercaptosuccinic acid, or succimer).

DMPS is another less risky chelating drug (also known as 2,3-Dimercapto-1-propanol, propanesulfonic acid, or sodium dimercaptopropanesulfonate).

Other drugs used for chelation have a much higher likelihood of causing serious side effects. Some of these include:

  • Alpha lipoic acid (also known as dihydrolipoic acid, lipoic acid, lipolate or thiotic acid)
  • Cysteine (also called acetylcysteine, cystein, cystin, L-cysteine, N-acetylcysteine, or NAC)
  • EDTA (also called H4EDTA, diaminoethanetetraacetic acid, edetic acid, edetate, ethylenedinitrilotetraacetic acid, tetrine acid, trilon BS, vinkeil 100, versene acid, or warkeelate acid)

Side Effects

Even when used appropriately in a clinical setting, chelation can have side effects ranging from dizziness and nausea to a headache and diarrhea. When used inappropriately and/or without proper supervision, chelation can have very serious side effects that can be life-threatening. Some of these include:

  • Low blood pressure
  • Cardiac issues
  • Seizures
  • Brain damage
  • Liver damage
  • Kidney damage
  • Dangerously low calcium levels
  • Anemia

Unfortunately, many parents have chosen to chelate their children at home without medical supervision—this has led to health issues ranging from nausea and diarrhea to even death in one case.

It's important to understand that heavy metals such as iron and copper are actually essential to the body's proper functioning.

Over-exposure to certain metals can cause serious problems, but the removal of all heavy metals can lead to similarly serious outcomes.

Research Claims

In 2003, practitioners of the DAN! protocol recorded that they saw many positive changes in people with autism who had taken DMSA, including the "rapid progression of language ability, improved social interaction, improved eye contact, and decreased self-stimulatory behaviors (stimming)."

Similar claims were made in multiple studies. All of these studies have flaws, however. Some of these errors are so significant that they do not provide any meaningful evidence. According to one meta-study, which included studies from multiple databases, "no clinical trial evidence was found to suggest that pharmaceutical chelation is an effective intervention for ASD." The study went on to claim that the risks outweighed the "proven benefits."

Among the potential risks of the treatment, the study found included hypocalcemia, renal impairment, and one reported death.

The study concluded, "Before further trials are conducted, evidence that supports a causal link between heavy metals and autism and methods that ensure the safety of participants are needed."

There is not an accepted and proven link between heavy metals and autism. Therefore, chelation therapy is not only potentially dangerous but also medically unfounded.

Chelation Today

Today, chelation therapy remains on the list of alternative treatments for autism. Several well-known organizations, including TACA (Talk About Curing Autism), continue to promote chelation as one of several biomedical treatments for autism. It is still possible to find doctors willing to use chelation on children with autism, and there are still parents willing to try this approach as a last or nearly-last resort.

Chelation, along with many other alternative or biomedical treatments (such as hyperbaric oxygen treatment and stem cell treatment) are unlikely to disappear anytime soon. There are many reasons for this.

Firstly, it is rare for parents to have definitive information about the cause of a child's autism. While there are many treatments for autism, none cure for the core symptoms. It is true that some children with autism improve dramatically over time—some children even improve to such a degree that they are no longer diagnosable as autistic.

Many children with autism seem to develop more or less normally until after the first year of life. The onset of autistic symptoms often coincides with the administration of specific childhood vaccinations. A minority of children with autism have co-morbid physical issues, such as gastrointestinal and skin problems, which parents assume to be related to their autism.

It is not always clear what a child with autism will respond to and how the condition will change over time. For these reasons and more, not all parents dismiss alternative treatments for autism. However, it is key to discuss any type of treatment with your child's doctor—equally important is to not overlook the potential and serious risks of therapy such as chelation.


It isn't easy to separate legitimate therapies from questionable therapies, and it's very tempting for parents to explore alternative options when mainstream medicine fails their children. The reality is that, in some circumstances, alternative methods of treatment can be helpful—there is no one-size-fits-all approach to selecting autism therapies.

If you are considering a non-mainstream option, however, try using these questions to help guide your decisions:

  • Who is recommending this option and what do they have to gain if you accept?
  • What do reliable sources such as the CDC (Centers for Disease Control and Prevention) or NIMH (National Institute of Mental Health) have to say about this particular treatment?
  • What are the potential risks related to using this treatment?
  • What methods are in place to ensure your child's safety?
  • How will you measure changes or improvements in your child's autism symptoms?

A Word From Verywell

In general, any treatment that the CDC and/or NIMH warns against and which carries a high risk of injury to your child should be avoided. This doesn't mean, however, that there aren't any options worth considering outside of those recommended by your pediatrician or offered by your child's school. It does mean that you, as the parent or guardian, must be extremely careful about exposing your child to a therapy that has the potential for harm.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Lisa Jo Rudy
Lisa Jo Rudy, MDiv, is a writer, advocate, author, and consultant specializing in the field of autism.