Recruitment began on 17<sup>th</sup> August 2020 and the updated expected recruitment end date is 1<sup>st</sup> August 2021.<h4>Trial registration</h4>The protocol was registered before starting subject recruitment under the title: Evaluation of the effect of recombinant erythropoietin on the improvement of COVID-19 patients, IRCT20200509047364N1, at Iranian Registry of clinical trials ( https://en.irct.ir/trial/49282 ) on 2020/08/09.<h4>Full protocol</h4>The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). Here, EPO is linked to COVID-19.