A lead poisoning drug, a fatal mix-up and a trial that failed

Chelation is unusual among the procedures sold for clearing toxins from the body, because it is also a genuine, FDA-approved medicine. For a child with severe lead poisoning, a chelating drug, one that binds a metal in the bloodstream so the body can excrete it, is standard treatment. Offered for clogged arteries, autism or a vague load of heavy metals, the same procedure has a different record.

That record includes three deaths described by the Centers for Disease Control and Prevention in 2006, a drug whose approvals the Food and Drug Administration withdrew in 2008, and two federally funded heart trials. The second trial, published in August 2024, cut blood lead by 61 percent, and heart attacks, strokes, deaths and related events came out essentially identical to placebo.

This article covers procedures performed on a person: intravenous chelation, colon irrigation, coffee enemas, ionic foot baths and foot pads, and sweating protocols. It starts with chelation’s approved use, because that is the clearest way to see what went wrong.

What chelation is approved to do

Two of the drugs FDA has approved for lead poisoning show how narrow the approved use is.

Edetate calcium disodium is given by injection. Its label, revised in January 2025, covers lowering blood and body stores of lead in acute and chronic lead poisoning, including the brain injury severe poisoning can cause, in children and adults. It adds that chelation does not replace ending the exposure, and its boxed warning says the drug can produce fatal toxic effects.

Succimer is a capsule taken by mouth. Its label limits it to children aged 1 and older whose blood lead is above 45 micrograms per deciliter, and says it is not for preventing poisoning while a child stays in a lead-contaminated environment.

Both answer one measured problem, confirmed by a blood test. The Oregon Medical Board put the principle in writing in a statement adopted in 2013 and amended in April 2025. Providers, it says, should chelate only after heavy metal toxicity is diagnosed by a blood test or another accepted test done without a chelating drug first.

A third drug looks almost identical on paper. Edetate disodium differs from the lead treatment by one word, calcium, and that word carries the safety: without it, the drug drives blood calcium down. CDC noted that its package insert indicated it for emergencies in which blood calcium is dangerously high.

Three deaths in a 2006 CDC report

On March 3, 2006, CDC’s Morbidity and Mortality Weekly Report described three people who died of hypocalcemia, a dangerous drop in blood calcium, during chelation in Texas, Pennsylvania and Oregon between 2003 and 2005.

The Texas case shows how narrow the gap was. A 2-year-old girl with a venous blood lead of 48 micrograms per deciliter, above the line where the oral drug’s label begins, was admitted in February 2005. Her orders first listed edetate disodium, were corrected to edetate calcium disodium, and she received the correct drug that day.

At 4 a.m. the next day she was given edetate disodium instead. About an hour later her serum calcium was 5.2 milligrams per deciliter, against a pediatric normal range of 8.5 to 10.5, and she died of cardiac arrest that morning. CDC reported that the two drugs’ brand names had been used interchangeably.

She had a real diagnosis and an approved treatment, and died because one drug was given in place of its near-namesake.

The second was a 5-year-old boy with autism receiving intravenous edetate disodium in a Pennsylvania physician’s office in August 2005. The coroner traced his death to brain injury after heart muscle damage from low calcium associated with the drug. CDC’s report records no lead poisoning diagnosis. A 2008 case report from the Pittsburgh Poison Center added that he was on his third treatment, and that only after his death was it established he had received edetate disodium rather than the calcium form.

The third was a 53-year-old woman who received 700 milligrams of intravenous EDTA at a naturopathic clinic in Oregon in August 2003, her fourth such treatment that year. She lost consciousness 10 to 15 minutes into the infusion, and the medical examiner attributed her death to an abnormal heart rhythm from low calcium associated with it. The state’s naturopathic licensing board was still investigating which drug she had received.

CDC’s conclusions were blunt. Edetate disodium should never be used for lead or other heavy metal poisoning in children, and hospital pharmacies should reconsider stocking it. Chelation for autism and coronary artery disease, the agency wrote, lacked accepted scientific support. A 2015 Cochrane review later found only one eligible randomized trial in autism and judged that the risks of chelation for that purpose outweigh any proven benefit.

What FDA did next

Between December 2007 and April 2008, FDA asked the companies holding the three approved applications for edetate disodium injection to let it withdraw them. Children and adults, it said, had died after being given the drug by mistake. The withdrawal took effect June 12, 2008. The Federal Register notice records that the original brand-name product had been approved in 1959 on the basis of safety alone.

In October 2022 FDA also listed edetate disodium, except for eye use, among bulk ingredients that may present significant safety risks when compounded by outsourcing facilities, a category of compounders that register with FDA. The reason was the same: providers mixing up the two edetates.

Both federally funded chelation heart trials, described next, used edetate disodium-based infusions. Inside those closely monitored trials, serious adverse events were no more common with chelation than with placebo. The National Center for Complementary and Integrative Health puts them at 11.9 against 14.6 percent in the first trial and 16.8 against 16.6 percent in the second. The deaths in CDC’s report happened outside any trial.

Two heart trials, told in order

The first trial cleared its bar by a thousandth

The Trial to Assess Chelation Therapy, known as TACT, appeared in JAMA in March 2013. Led by Gervasio Lamas, it enrolled 1,708 heart attack survivors aged 50 or older at 134 sites in the United States and Canada. Each got 40 infusions of placebo or a solution of disodium EDTA, vitamin C, B vitamins, electrolytes, the anesthetic procaine and the blood thinner heparin.

The main outcome bundled death, another heart attack, stroke, procedures to reopen arteries and hospital stays for chest pain. It occurred in 26 percent of the chelation group and 30 percent of the placebo group. Because the investigators had checked the data many times along the way, the result needed a P value of .036 or lower to count. It came in at .035. Deaths on their own did not differ, 10 percent against 11 percent.

The authors called the benefit modest, noted that many prevented events were artery-opening procedures, and wrote that the results did not support routine chelation after a heart attack. In the same issue, Steven E. Nissen argued in an editorial that the results could not be accepted as reliable. He cited uneven withdrawals, 174 from placebo against 115 from chelation, and more than 60 percent of patients enrolled at sites described as complementary and alternative medicine centers. He also objected to an unblinded sponsor, which he called a serious deviation, to 11 interim analyses, and to two outcome components, artery procedures and angina admissions, that he considered less reliable.

One finding kept the question open. Among 633 participants with diabetes, a subgroup named in advance, the main outcome occurred in 25 percent on chelation against 38 percent on placebo, a result that survived correction for testing many subgroups. Deaths were 10 against 16 percent, a gap NCCIH’s summary reports as a 43 percent reduction, but it did not survive the correction. Among 1,075 participants without diabetes, chelation showed no effect.

In this library’s vocabulary, TACT left chelation for heart disease with positive trial evidence, contested interpretation. A disputed subgroup has one honest remedy: test it directly.

The second trial removed the lead and changed nothing else

TACT2 enrolled only people aged 50 or older with diabetes and a previous heart attack, at 88 sites in the United States and Canada. Of 1,000 randomized, 959 received at least one of 40 weekly infusions of an edetate disodium-based solution or placebo, and they were followed for a median of four years. Four National Institutes of Health institutes paid for it, and JAMA published the results on August 14, 2024.

The main outcome occurred in 35.6 percent of the chelation group and 35.7 percent of the placebo group. Cardiovascular death, heart attack or stroke: 18.4 against 19.7 percent. Death from any cause: 17.4 against 17.6 percent. None of these differences was statistically significant.

Chemically, though, the infusions did their job. Median blood lead in the chelation group fell from 9.03 micrograms per liter to 3.46 by the 40th infusion, a 61 percent drop, while the placebo group went from 9.3 to 8.7. The investigators wrote in JAMA: “Despite effectively reducing blood lead levels, EDTA chelation was not effective in reducing cardiovascular events …”

The trial measured micrograms per liter; the succimer label uses micrograms per deciliter, a unit ten times larger. Participants started at a median of about 0.9 micrograms per deciliter, roughly one-fiftieth of the label’s threshold and of the Texas child’s level. A 2024 baseline paper from the trial found their metal levels largely similar to those of comparable adults in a federal national health survey. These were people with ordinary American lead levels, not poisoned patients.

The investigators, as NCCIH summarized them, pointed to more advanced disease in TACT2, possibly lower lead exposure, and a trial perhaps too small to catch a modest effect. NCCIH’s own August 2024 conclusion is that because TACT2 did not reproduce TACT, the findings do not support chelation to lower cardiovascular risk in people with diabetes and a prior heart attack.

The arithmetic narrows what remains. TACT’s diabetes subgroup suggested a hazard ratio of 0.59, roughly a 41 percent cut in events. TACT2’s confidence range ran from 0.76 to 1.16, which excludes an effect that large. So the large benefit the first trial suggested is tested and not supported. A smaller benefit has not been ruled out.

The urine test used to justify chelation

Outside approved lead treatment, chelation is often justified by a provoked, or post-challenge, urine test: the patient receives a chelating drug first and urine is collected afterward. Writing in the Journal of the American Board of Family Medicine in 2010, physicians David Vearrier and Michael I. Greenberg explained the problem. The drug itself raises metal concentrations in urine, producing falsely elevated results, and no normal reference range exists for provoked samples. In the case they described, a patient’s ordinary 24-hour urine mercury was normal while the provoked sample was reported as elevated.

The American College of Medical Toxicology, as quoted by the Oregon Medical Board, says this testing “has not been scientifically validated, has no demonstrated benefit, and may be harmful …” The board states that it does not meet the standard of care for diagnosing heavy metal toxicity.

Colon irrigation and coffee enemas

Colon irrigation

FDA regulates colonic irrigation systems, machines that run water into the colon through a nozzle in the rectum, under a rule that sorts them by purpose. For cleansing when medically indicated, such as before an X-ray or endoscopy, the device is Class II, a moderate-risk category. For any other use, explicitly including routine cleansing for general well-being, it is Class III, the highest-risk category, which requires an approved premarket application before it can be sold for that purpose.

The evidence runs thin in one direction and thicker in the other. A 2009 systematic review in the American Journal of Gastroenterology by Ruben Acosta and Brooks Cash found no methodologically rigorous controlled trials supporting colon cleansing for general health, alongside multiple case reports and case series of harm. NCCIH says harm is more likely in people with a history of digestive disease, colon surgery, severe hemorrhoids, kidney disease or heart disease. It adds that FDA and the Federal Trade Commission have acted against companies over colon-cleansing devices marketed for unapproved uses.

The best-documented outbreak is old. In 1982 the New England Journal of Medicine reported at least 36 cases of amebiasis, an intestinal parasite infection, among people who had colonic irrigation at one chiropractic clinic in western Colorado between 1978 and 1980. Tested after routine cleaning, the machine was heavily contaminated with fecal bacteria, and ten patients needed colectomy, surgery to remove the colon.

Coffee enemas

Coffee enemas spread through the Gerson regimen, a program developed by Max Gerson in the 1930s and promoted above all for cancer. Its proponents hold that compounds in coffee act on the liver to speed the flushing of toxins through bile. That is the regimen’s own explanation, not an established mechanism.

A 2020 systematic review led by researchers at Seoul National University searched 12 databases and found no study measuring whether self-administered coffee enemas work. It found nine case reports of harm. Seven recent ones described colitis, inflammation of the colon, in four cases and rectal burns or perforation in three.

Two older reports were graver. One, published in JAMA in 1980, described two people who used coffee enemas very frequently and died with severely depleted sodium and chloride, which its authors blamed on the salt-free fluid. Another described a woman with breast cancer that had spread to her liver who died of a bloodstream infection with gut bacteria. The National Cancer Institute’s patient summary on the regimen, last updated in January 2015, notes published reports of three deaths possibly related to coffee enemas.

Foot baths, foot pads and sweat

An ionic foot bath is a tub of salted water holding an electrode array. You rest your feet in it for half an hour, and whatever collects in the water is presented as toxins drawn out through the soles, at sessions that have sold for upwards of $75. The most careful test this library found came from inside complementary medicine, at the Canadian College of Naturopathic Medicine in Toronto.

Researchers there ran the machine with no feet in the water, then with six healthy volunteers over four weekly sessions, using a laboratory blinded to each sample. The elements that rose most, with or without feet, were iron, chromium, nickel, molybdenum, manganese and silicon, closely matching the 316-grade stainless steel of the electrode, which corrodes under direct current in salt water. Adding feet made no significant difference to total toxic elements, and urine and hair showed no rise in elimination. The paper, published online in November 2011 and dated 2012 by its journal, found no evidence the baths remove toxic elements.

Adhesive foot pads worn overnight produced a federal case. In January 2009 the FTC sued a marketer whose ads said the pads pulled out heavy metals, toxins and parasites and treated conditions from depression to diabetes. Under an October 2010 order, the company and two principals faced a $14.5 million judgment, equal to total sales and suspended because they could not pay, and a ban on marketing any supplement, food, drug or medical device. For ionic foot baths, this library looked for a comparable action by FDA, the FTC or a foreign regulator and found none.

Sweating protocols, usually sauna sessions, rest on the idea that sweat carries metals out. A 2012 systematic review by Margaret Sears and colleagues found that in highly exposed people, sweat concentrations of arsenic, cadmium, lead and mercury generally exceeded those in blood plasma or urine. But it drew on 24 reports with widely varying methods. A 2019 physiology review by Lindsay Baker, a scientist at a sports-drink maker’s research institute, judged sweat’s role in clearing toxicants minor next to the kidneys and gut. The claim that sauna sessions lower body stores of metals sits at insufficient evidence to assess; the 2012 reviewers themselves called for properly sized trials.

Questions worth asking first

Five questions to bring to any clinic, and to your own clinician:

1. What exactly is being removed, and which test showed it? A blood lead level is a standard test. A provoked urine sample is not.
2. Which drug, by its full name? Edetate calcium disodium and edetate disodium differ by one word, and that word separated treatment from tragedy in Texas.
3. Who watches calcium and kidney function during an infusion? NCCIH names low calcium and kidney damage as chelation’s most important serious side effects.
4. What is the device’s FDA status for this exact use? A colon irrigation system’s Class II status covers medically indicated cleansing only.
5. What happened when it was tested? For heart disease, the later, more focused trial was negative.

Worry about lead exposure starts with a blood test ordered by a clinician, and CDC’s 2006 report urged primary care providers to consult lead treatment experts before using chelation drugs. Tingling around the mouth or in the hands, muscle spasms, or a racing or irregular heartbeat during or after an infusion are emergency symptoms. After a colonic or enema, severe abdominal pain, fever or rectal bleeding needs prompt medical care; the case reports in this field began with exactly those complaints.

The Takeaway

Removing a substance from the body and improving health are two different claims, and in TACT2 the first did not deliver the second: lead fell by 61 percent and heart events did not move. Chelation’s approved role is narrow, treating metal poisoning such as lead poisoning confirmed by a blood test, with drugs whose names must be read in full. For colon irrigation, coffee enemas, foot baths and sweat protocols, no health benefit has been shown, while the harms on record are specific: a contaminated machine spreading infection, burns and colitis, and salt loss linked to two deaths.

Sources

1. Centers for Disease Control and Prevention. “Deaths Associated with Hypocalcemia from Chelation Therapy: Texas, Pennsylvania, and Oregon, 2003-2005. MMWR 55(08):204, March 3, 2006.” cdc.gov
2. Food and Drug Administration, Federal Register (reproduction hosted by Justia). “Withdrawal of approval of one new drug application and two abbreviated new drug applications for edetate disodium injection, effective June 12, 2008. Federal Register Vol. 73, No. 114, pp. 33440-33441, Docket FDA-2008-0321.” docs.regulations.justia.com
3. Food and Drug Administration. “Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (edetate disodium, except ophthalmic, added to 503B category 2 on October 12, 2022; content current as of 04/22/2026).” fda.gov
4. National Library of Medicine, DailyMed (FDA-approved labeling). “Edetate calcium disodium injection, prescribing information (revised 01/2025).” dailymed.nlm.nih.gov
5. National Library of Medicine, DailyMed (FDA-approved labeling). “Succimer capsules, for oral use, prescribing information (revised 9/2024).” dailymed.nlm.nih.gov
6. National Center for Complementary and Integrative Health, National Institutes of Health. “Chelation for Coronary Heart Disease: What You Need To Know (content last updated August 2024).” nccih.nih.gov
7. National Center for Complementary and Integrative Health, National Institutes of Health. “In a Large Multicenter Trial, Chelation Therapy Did Not Reduce Cardiovascular Disease Events in Patients With Diabetes and a History of Heart Attack (research results, August 14, 2024).” nccih.nih.gov
8. National Center for Complementary and Integrative Health, National Institutes of Health. “Detoxes and Cleanses: What You Need To Know (content last updated March 2025; used only for colon-cleansing procedure risks and enforcement).” nccih.nih.gov
9. JAMA. “Lamas GA, Goertz C, Boineau R, et al. "Effect of disodium EDTA chelation regimen on cardiovascular events in patients with previous myocardial infarction: the TACT randomized trial." JAMA, 2013. PubMed. DOI: 10.1001/jama.2013.2107.” pubmed.ncbi.nlm.nih.gov
10. JAMA. “Nissen SE. "Concerns about reliability in the Trial to Assess Chelation Therapy (TACT)." JAMA, 2013;309(12):1293-4. PubMed. DOI: 10.1001/jama.2013.2778.” doi.org
11. Circulation: Cardiovascular Quality and Outcomes. “Escolar E, Lamas GA, Mark DB, et al. "The effect of an EDTA-based chelation regimen on patients with diabetes mellitus and prior myocardial infarction in the Trial to Assess Chelation Therapy (TACT)." Circulation: Cardiovascular Quality and Outcomes, 2014. PubMed. DOI: 10.1161/CIRCOUTCOMES.113.000663.” pubmed.ncbi.nlm.nih.gov
12. JAMA. “Lamas GA, Anstrom KJ, Navas-Acien A, et al. "Edetate Disodium-Based Chelation for Patients With a Previous Myocardial Infarction and Diabetes: TACT2 Randomized Clinical Trial." JAMA, 2024. PubMed. DOI: 10.1001/jama.2024.11463.” pubmed.ncbi.nlm.nih.gov
13. American Heart Journal. “Navas-Acien A, Santella RM, Joubert BR, et al. "Baseline characteristics including blood and urine metal levels in the Trial to Assess Chelation Therapy 2 (TACT2)." American Heart Journal, 2024. PubMed. DOI: 10.1016/j.ahj.2024.04.005.” pubmed.ncbi.nlm.nih.gov
14. Clinical Toxicology. “Baxter AJ, Krenzelok EP. "Pediatric fatality secondary to EDTA chelation." Clinical Toxicology, 2008. PubMed. DOI: 10.1080/15563650701261488.” pubmed.ncbi.nlm.nih.gov
15. Cochrane Database of Systematic Reviews. “James S, Stevenson SW, Silove N, Williams K. "Chelation for autism spectrum disorder (ASD)." Cochrane Database of Systematic Reviews, 2015. PubMed. DOI: 10.1002/14651858.CD010766.pub2.” pubmed.ncbi.nlm.nih.gov
16. Oregon Medical Board. “Statement of Philosophy on Chelation Therapy (adopted October 2013; amended April 2025; quotes the American College of Medical Toxicology position on post-chelator challenge testing).” oregon.gov
17. Journal of the American Board of Family Medicine. “Vearrier D, Greenberg MI. "Care of Patients Who Are Worried about Mercury Poisoning from Dental Fillings." J Am Board Fam Med, 2010;23(6):797-798.” jabfm.org
18. Electronic Code of Federal Regulations. “21 CFR 876.5220, Colonic irrigation system (Class II when medically indicated; Class III for other uses including routine cleansing for general well-being).” ecfr.gov
19. American Journal of Gastroenterology. “Acosta RD, Cash BD. "Clinical effects of colonic cleansing for general health promotion: a systematic review." American Journal of Gastroenterology, 2009. PubMed. DOI: 10.1038/ajg.2009.494.” pubmed.ncbi.nlm.nih.gov
20. New England Journal of Medicine. “Istre GR, Kreiss K, Hopkins RS, et al. "An outbreak of amebiasis spread by colonic irrigation at a chiropractic clinic." New England Journal of Medicine, 1982. PubMed. DOI: 10.1056/NEJM198208053070603.” pubmed.ncbi.nlm.nih.gov
21. Medicine (Baltimore). “Son H, Song HJ, Seo HJ, Lee H, Choi SM, Lee S. "The safety and effectiveness of self-administered coffee enema: A systematic review of case reports." Medicine (Baltimore), 2020. PubMed. DOI: 10.1097/MD.0000000000021998.” pubmed.ncbi.nlm.nih.gov
22. National Cancer Institute. “Gerson Therapy (PDQ), Patient Version (last updated January 7, 2015; no longer updated).” cancer.gov
23. Journal of Environmental and Public Health. “Kennedy DA, Cooley K, Einarson TR, Seely D. "Objective assessment of an ionic footbath (IonCleanse): testing its ability to remove potentially toxic elements from the body." Journal of Environmental and Public Health, 2012 (published online November 29, 2011). PubMed. DOI: 10.1155/2012/258968.” pubmed.ncbi.nlm.nih.gov
24. Federal Trade Commission. “Press release announcing charges against a marketer of overnight foot pads and two principals for deceptive advertising (January 28, 2009).” ftc.gov
25. Federal Trade Commission. “At FTC's Request, Judge Imposes Ban on Marketers of Detox Foot Pads (November 4, 2010).” ftc.gov
26. Journal of Environmental and Public Health. “Sears ME, Kerr KJ, Bray RI. "Arsenic, cadmium, lead, and mercury in sweat: a systematic review." Journal of Environmental and Public Health, 2012. PubMed. DOI: 10.1155/2012/184745.” pubmed.ncbi.nlm.nih.gov
27. Temperature (Austin). “Baker LB. "Physiology of sweat gland function: The roles of sweating and sweat composition in human health." Temperature (Austin), 2019. PubMed. DOI: 10.1080/23328940.2019.1632145.” pubmed.ncbi.nlm.nih.gov