A compound for use in a method of treating a patient suffering from a disease for which treatment with cysteamine is indicated comprising administering to the patient an effective amount of said compound, wherein said compound is a compound or a disulfide thereof selected from the group consisting of: wherein: R 1 and R 2 are independently selected from the group consisting of H and C 1-5 alkyl; or R 1 and R 2 , taken together with the carbon atom to which they are attached, form a 3-, 4-, 5-, 6-, 7-, or 8-membered carbocyclic ring; R 3 and R 4 are independently selected from the group consisting of H and C 1-5 alkyl; or R 3 and R 4 , taken together with the carbon atom to which they are attached, form a 3-, 4-, 5-, 6-, 7-, or 8-membered carbocyclic ring; R 5 and R 6 are independently selected from the group consisting of H and C 1-5 alkyl; or R 5 and R 6 , taken together with the nitrogen atom to which they are attached, form a 3-, 4-, 5-, 6-, 7-, or 8-membered heterocyclic ring; R 7 and R 8 are independently selected from the group consisting of H and C 1-5 alkyl; or R 7 and R 8 , taken together with the carbon atom to which they are attached, form a 3-, 4-, 5-, 6-, 7-, or 8-membered carbocyclic ring; or R 4 and R 6 , taken together with the atoms to which they are attached, form a 4-, 5-, 6-, 7-, 8-, 9-, or 10-membered heterocyclic ring, and wherein the disease is selected from the group consisting of cystinosis, fatty liver disease, fibrosis, a thrombotic disease, a neurological disease or disorder, inflammation and cancer, an MECP-2 related disorder selected from the group consisting of Rett syndrome, autism, pervasive development disorder, non-syndromic mental retardation, idiopathic neonatal encephalopathy and idiopathic cerebral palsy, and an inherited mitochondrial disease selected from the group consisting of Friedreich's ataxia, Leber's hereditary optic neuropathy (LHON), myoclonic epilepsy and ragged-red fibers, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like syndrome (MELAS), Kearn-Sayre syndrome and subacute necrotizing encephalopathy (Leigh's Syndrome). R 1 and R 2 are independently selected from the group consisting of H and C 1-5 alkyl; or R 1 and R 2 , taken together with the carbon atom to which they are attached, form a 3-, 4-, 5-, 6-, 7-, or 8-membered carbocyclic ring; R 3 and R 4 are independently selected from the group consisting of H and C 1-5 alkyl; or R 3 and R 4 , taken together with the carbon atom to which they are attached, form a 3-, 4-, 5-, 6-, 7-, or 8-membered carbocyclic ring; R 5 and R 6 are independently selected from the group consisting of H and C 1-5 alkyl; or R 5 and R 6 , taken together with the nitrogen atom to which they are attached, form a 3-, 4-, 5-, 6-, 7-, or 8-membered heterocyclic ring; R 7 and R 8 are independently selected from the group consisting of H and C 1-5 alkyl; or R 7 and R 8 , taken together with the carbon atom to which they are attached, form a 3-, 4-, 5-, 6-, 7-, or 8-membered carbocyclic ring; or R 4 and R 6 , taken together with the atoms to which they are attached, form a 4-, 5-, 6-, 7-, 8-, 9-, or 10-membered heterocyclic ring, and wherein the disease is selected from the group consisting of cystinosis, fatty liver disease, fibrosis, a thrombotic disease, a neurological disease or disorder, inflammation and cancer, an MECP-2 related disorder selected from the group consisting of Rett syndrome, autism, pervasive development disorder, non-syndromic mental retardation, idiopathic neonatal encephalopathy and idiopathic cerebral palsy, and an inherited mitochondrial disease selected from the group consisting of Friedreich's ataxia, Leber's hereditary optic neuropathy (LHON), myoclonic epilepsy and ragged-red fibers, mitochondrial encephalomyopathy, lactic acidosis, and stroke-like syndrome (MELAS), Kearn-Sayre syndrome and subacute necrotizing encephalopathy (Leigh's Syndrome). <EOS>