The present invention describes a method for the treatment of tall oil pitch (TOP), said method comprising heating the TOP and optionally additives including water and steam to a temperature of at least 300° C.; maintaining the temperature in the reactor at 300° C. or higher for a period of time to enable thermal treatment of the TOP to act on components thereof to produce fatty acids and/or rosin acids, and/or derivatives thereof, and/or unsaponifiables and/or derivatives having lower molecular weight compared to the high molecular weight components with molecular weights of at least 350 g/mole present in the original TOP, to yield a modified TOP material with lower viscosity.