Dimercaptosuccinic acid

Dimercaptosuccinic acid, or DMSA, is the chemical compound with the formula HO2CCH(SH)CH(SH)CO2H. This colourless solid contains two carboxylic acid and two thiol groups, the latter being responsible for the mildly unpleasant odour of this dicarboxylic acid. It occurs in two diastereomeric forms, meso and the chiral dl forms. The meso isomer is used as chelating agent.

Meso 2,3-dimecaptosuccinic acid is used to sequester heavy metals such as mercury and lead for excretion. DMSA can cross the blood-brain barrier, and thus is useful for extracting heavy metals from the brain.

DMSA is also called succimer and is sold under the brand name Chemet®. The dimethylester is also known.