It is so flexible and large that it potentially sticks to almost anything; it is not a precision small molecule inhibitor of a protease. Ritonavir is also a protease class specific inhibitor and was considered in conjunction with Liponavir as an inhibitor of Mpro due to latter's structure. Many molecules of this size and flexibility have been both computationally and in the lab examined as possible viable inhibitors of SARS-Cov-2 Mpro .