Fermi Pasta Ulam (FPU) recurrence process describes the ability of a nonlinear system to excite multiple modes and then to return to its initial state. In fiber optics, such process has been investigated within the framework of modulation instability (MI) [1], corresponding to growth of weak perturbations at the expense of a strong pump. Nonlinear stage of MI and FPU recurrences in optical fibers have been widely investigated and many results have been obtained with an efficient compensation of the losses [2]. Investigations on water waves [3] demonstrated that dissipation of their water tank forces the system to operate in a single regime. Here, we provide a deeper and complete study on the impact of dissipation of the FPU dynamics. Thanks to a fiber optics system, we have been able to control the loss coefficient, allowing us to trigger the different corresponding FPU regimes. Using a setup similar to the one in [2] and based on a multiple HOTDR system, we managed to record FPU recurrences in power and phase along the fiber length as a function of the loss, Fig. 1. The dissipation is controlled thanks to a counter-propagating Raman pump whose power is tuned to get an effective loss coefficient. A direct relation between the Raman pump power and effective loss coefficient is obtained, allowing a direct comparison between experiments (left panel) and simulations (right panel). Three different regions are discernible. In the 3 rd