EPA prevents a TNF-α-mediated reduction in myotube size. C2C12 cells were induced to differentiate in the presence or absence of TNF-α (20 ng/ml) and EPA (50 μM). EPA was added together with TNF-α as a co-treatment (EPA+TNF) or, alternatively EPA was administered alone for a 2 hour pre-treatment after which it was withdrawn and replaced by TNF-α alone in DM (pEPA+TNF). Incubations were continued for 5 days in DM with replenishment of EPA and TNF-α at media changes. Myotube diameters were calculated for DAPI and MyHC stained cells from each treatment. Data are expressed as means ± standard error of mean (SEM) from 3 independent experiments (*p < 0.05 v. control; #p < 0.05 v. TNF-α; **NS v. control).