An orally administered antihyperlipidemia composition according to the present invention includes from about 250 to about 3000 parts by weight of nicotinic acid, and from about 5 to about 50 parts by weight of hydroxypropyl methylcellulose. Also, a method of treating hyperlipidemia in a hyperlipidemic having a substantially periodic physiological loss of consciousness, includes the steps of forming a composition having an effective antihyperlipidemic amount of nicotinic acid and a time release sustaining amount of a swelling agent. The method also includes the step of orally administering the composition to the hyperlipidemic once per day "nocturnally," that is in the evening or at night.