When acting as an antioxidant, ethoxyquin is converted mainly to a 1,8′‐dimer and to a quinone‐imine, with the latter itself acting as a powerful antioxidant. The 8‐methyl derivative of ethoxyquin was prepared in the expectation that this would not form a dimer but more quinone‐imine and, therefore, be a more powerful antioxidant. On oxidation of 8‐methylethoxyquin, the dimer was absent and the quinone‐imine was formed in high yield. Despite this, 8‐methylethoxyquin was a less efficient antioxidant than ethoxyquin in fish oil and meal.