Cystine analogs that improve the solubility of L-cystine in urine for treatment of cystinuria and which have the structure: and pharmaceutically acceptable salts, solvates and prodrugs thereof, wherein each R and R′ pair are independently selected from (i) or (ii); (i) R and R′ are independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alcohol, substituted or unsubstituted aryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclic, and substituted or unsubstituted heteroaryl, or (ii) R and R′ together form a substituted or unsubstituted heterocyclic ring structure, or a substituted or unsubstituted heteroaryl ring structure; X is hydrogen, or an alkyl; and Y is O or S.