ABSTRACT.The lipid‐lowering effects of 3 g of the nicotinic acid derivative pentaerythritoltetranico‐tinate (niceritrol) given either 1 gx3 or 1.5 gx2 have been evaluated in 18 subjects with hyperlipoprotein‐aemia. When 1 g niceritrol was given three times daily, the serum TG concentration fell from 3.14+ 0.48 to 1.86+0.18 mmol/l (41% reduction) and the serum cholesterol concentration from 282+9 to 227+11 mg/100 ml (20% reduction). The same daily dose, given 1.5 g twice, did not significantly lower the serum TG concentration, and serum cholesterol was lowered by only 12 %. Niceritrol tablets prepared with a dissolution time of 60 or 90 min had identical lipid‐lowering properties. Although patients may find it practical to take niceritrol only twice daily, such a dose regimen has considerably less effect on elevated serum lipids than a thrice‐dail