Statins are administered daily, but because of their long half-lives, atorvastatin and rosuvastatin can be given every other day (q.o.d.). We examined the effect of q.o.d. statin therapy in 25 patients treated with either atorvastatin (mean dose, 18.8 mg q.o.d.) or rosuvastatin (mean dose, 9.7 mg q.o.d.). Low-density lipoprotein cholesterol decreased 43%, triglycerides (mean +/- SEM) decreased 22%+/-6%, and high-density lipoprotein cholesterol increased 9%+/-6% with q.o.d. atorvastatin (n=9; p<0.05 for all). Low-density lipoprotein cholesterol decreased 28%, triglycerides decreased 15%+/-6%, and high-density lipoprotein cholesterol increased 10%+/-5% with rosuvastatin q.o.d. (n=16; p<0.05 for all). We conclude that q.o.d. treatment with long-acting statins significantly improves serum lipid levels.