Policosanol

Policosanol (or polycosanol) is the generic term for a natural mixture of long chain alcohols extracted from plant waxes. It is used as a nutritional supplement intended to lower LDL cholesterol ("bad" cholesterol) and increase HDL cholesterol ("good" or "healthy" cholesterol) and to help prevent atherosclerosis, though some studies have raised questions about the effectiveness of policosanol.

Physical properties
Policosanol is a mixture of a few fatty alcohols derived from the waxes of such plants as sugar cane and yams, as well as beeswax. The most prevalent alcohol in policosanol is octacosanol, followed by triacontanol.

There is a much lower concentration of several other fatty alcohols: behenyl alcohol, lignoceryl alcohol, ceryl alcohol, 1-heptacosanol, 1-nonacosanol, 1-dotriacontanol, and geddyl alcohol.

Modulation of HMG-CoA reductase and bile acid absorption inhibition have been proposed as mechanisms.

Studies
Published studies have come to conflicting conclusions regarding the efficacy of policosanol in lowering LDL (i.e., "bad cholesterol") or raising HDL (i.e., "good cholesterol").,  despite a number of studies funded by the Cuban government, which produces and markets the drug, Older independent clinical trials found no evidence of the efficacy of policosanol, while more recent studies have found effect.