Alpha Lipoic Acid (ALA) is a common nutritional supplement that you can buy over the counter and is known to be a chelating agent while raising the glutathione levels in the blood.

Owing to the presence of two thiol groups, dihydrolipoic acid is a chelating agent. Lipoic acid administration can significantly enhance biliary excretion of inorganic mercury in rat experiments, although it is not known if this is due to chelation by lipoic acid or some other mechanism. Lipoic acid has the potential to cross the blood-brain barrier in humans unlike DMSA and DMPS, however its effectiveness is heavily dependent on the dosage and frequency of application.