Dimercaptosuccinic Acid (DMSA / Succimer)

Also known as: succimer, Chemet (brand), oral chelating agent

Other

In plain English

DMSA (succimer) is an oral medicine that binds heavy metals — mainly lead — so the body can remove them in urine. It is FDA-approved for lead poisoning in children with high blood-lead levels. Importantly, chelation lowers lead levels but has not been shown to improve thinking or behavior at moderate lead levels, so the priority is removing the source of exposure. 'Detox' chelation for vague symptoms is not evidence-based and carries risks.

The science

Succimer is a water-soluble dithiol chelator that forms stable, excretable complexes primarily with lead (and other heavy metals), lowering blood-lead concentrations. In the large randomized Treatment of Lead-Exposed Children (TLC) trial, succimer reduced blood lead but did not improve cognitive, behavioral, or neuropsychological outcomes in children with levels of 20-44 µg/dL, so chelation is reserved for higher levels and environmental abatement is central.

References

• Rogan WJ et al., chelation with succimer and neurodevelopment in lead-exposed children (TLC RCT), N Engl J Med 2001
• Bradberry S & Vale A, DMSA (succimer) in inorganic lead poisoning, Clin Toxicol 2009