D-004, a lipid extract of Roystonea regia fruits that prevents testosterone-induced prostate hyperplasia in rodents, and saw palmetto (SP) lipid extract, used to treat benign prostate hyperplasia, have been shown antioxidant effects. This randomized, double-blind study compared their antioxidant effects in forty healthy men randomised to D-004 or SP (320 mg/day) capsules for 8 weeks. D-004 significantly (p < 0.001) reduced plasma malondialdehyde (MDA) (32.7 %), sulphydril groups (SH-G) (24.6 %) and (p < 0.01) total hydroxyperoxides (TOH) (26.5 %) values and increased (p < 0.001) total antioxidant status (TAS) (44.1 %) and catalase (CAT) (100.0 %) activity. Treatment with SP lowered (p < 0.001) MDA (26.6 %), SH-G (24.1 %), (p < 0.01) TOH (26.3 %) values, and raised (p < 0.001) TAS (57.4 %) and (p < 0.01) CAT (85.7 %) activity. Both treatments were similarly effective and well tolerated. Concluding, D- 004 and SP (320 mg/day) for 8 weeks similarly reduced plasma lipid peroxidation (MDA, TOH) and protein oxidation (SH-G) markers, increased TAS and CAT activity and were well tolerated in healthy men.Colegio de Farmacéuticos de la Provincia de Buenos Aire