D-penicillamine is an optically active form of penicillamine having D-configuration. Pharmaceutical form (L-form is toxic) of chelating agent used to treat heavy metal poisoning. It has a role as a chelator, an antirheumatic drug, a drug allergen and a copper chelator. It is a penicillamine and a non-proteinogenic alpha-amino acid. It is an enantiomer of a L-penicillamine.