•Experimental analysis shows strong influence of l-Tyrosine on the oscillatory dynamics of the Bray-Liebhafsky reaction.•Two reaction pathways based on the interaction of l-Tyrosine with HIO or I2O were investigated to explain the experimental results.•The reaction pathway between l-Tyrosine and I2O showed better agreement with the experimental results. The impact of L-tyrosine on the dynamics of the Bray-Liebhafsky (BL) oscillatory reaction was investigated both experimentally and numerically. The study focused on the examination of the sensitivity of the BL reaction to L-tyrosine perturbation. The results obtained indicated possible pathways of influence. Simulations were carried out with and without L-tyrosine. The interaction of L-tyrosine with the BL reaction system was tested with two possible reactions. Display omitted