Probucol, sold under the trade name Lorelco among others, is an lipid-lowering agent[3] initially developed for the treatment of coronary artery disease.

Clinical use was discontinued in some countries after it was found that the drug may have the undesired effect of lowering HDL-C in patients with a previous history of heart disease.

[1][2] Possible serious adverse effects include ventricular arrhythmia (Torsades de pointes), syncope, gastrointestinal bleeding, peripheral neuritis, and rhabdomyolysis.

At a low dose (insufficient to affect LDL-C or HDL-C levels), it prevents the oxidation of cholestrol in LDLs.

Overall, probucol increases the capacity for reverse cholesterol transport, so the observed HDL-C reduction does not lead to a decrease in a patient's cholesterol-removing ability.

[13] After promising test results in mouse models, probucol is under study at Weston Brain Institute of McGill University as a possible aid in delaying the onset of Alzheimer's disease.

Succinobucol, the succinate ester of probucol, failed to demonstrate a useful degree of efficacy in clinical trials targeting acute coronary syndrome.

BO-653, another analogue, failed its phase II trial targeting atherosclerosis treatment and prevention of post-angioplasty restenosis.