Cystamine is an unstable liquid and is generally handled as the dihydrochloride salt, C4H12N2S2·2HCl, which is stable to 203-214 °C at which point it decomposes.

[3] Cystamine dihydrochloride is a useful reagent to derivatize various polymer monoliths for hydrophilic interaction liquid chromatography, as a crosslinking agent in the development of polymer hydrogels, and as a functional group in nanoparticles developed for siRNA and DNA delivery.

[6] Cystamine has also been studied as a potential medicinal compound in the case of Huntington's disease,[2] Alzheimer's disease,[7] carbon tetrachloride liver damage,[8] and inhibition of erythrocyte sickling[9] Cystamine has been shown to bind reversibly with purified DNA in vitro, and imparts a radiation-protective effect to treated DNA.

[citation needed] [12] Cystamine has also been shown to interact with the production of microtubule assemblies in bovine brain tissue.

[13] Multiple factors of potential cystamine toxicity have been described relating to hepatoxicity,[14] anti-coagulant activity[15] and skin sensitisation.

Cystamine in the body is reduced into cysteamine and RS-cysteamine mixed disulfide by thiol-disulfide exchange.