The prodrug fenofibrate, a synthetic phenoxy-isobutyric acid derivative, is rapidly hydrolyzed in vivo to form fenofibric acid, which alters plasma lipid levels by activating the peroxisome proliferator-activated receptor alpha. The micronized fenofibrate 200 mg capsule formulation, and the recently developed micronized fenofibrate 160 mg tablet formulation, are bioequivalent. Micronized fenofibrate 200 mg/day (capsules) increased high density lipoprotein cholesterol (HDL-C) levels significantly from baseline in up to 7098 patients with various dyslipidemias in noncomparative studies. Micronized fenofibrate 200 mg/day (capsules) produced significantly greater elevations in HDL-C levels than a variety of HMG-CoA reductase inhibitors in small, randomized, double-blind and nonblind studies in patients with dyslipidemia (n = 91 to 227). This formulation of fenofibrate and gemfibrozil produced similar increases in HDL-C levels in a randomized, double-blind study (n = 234). Micronized fenofibrate 160 mg once daily (tablet) increased HDL-C levels significantly from baseline by 10.6 to 14.5% in patients with type IIa or IIb dyslipidemia (n = 353) in two noncomparative studies. Additionally, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglyceride levels, and LDL-C to HDL-C and TC to HDL-C ratios were lowered significantly from baseline. The tablet and capsule formulations of fenofibrate were both generally well tolerated in two noncomparative studies in 375 or 9884 patients. In double-blind, placebo-controlled trials in a total of 804 patients, the pooled incidences of individual adverse events were generally similar with fenofibrate and placebo.