Abstract: The invention relates to an improved enhanced recovery method using polymers, wherein these polymers are preserved from mechanical degradation by adding an additive comprising sacrificial compounds. The sacrificial compounds are preferentially degraded instead of the active polymers, thus allowing optimized recovery of the oil in the petroleum reservoir. The sacrificial compounds can be polymers of same nature as the active polymers, but of higher molecular weight, or polymers of different nature having more fragile bonds. The sacrificial compound(s) is/are selected according to a lesser resistance to mechanical degradation, in comparison with the active polymers of the solution allowing enhanced recovery.