Unlike previous outbreaks like SARS and MERS, caused by corona family viruses, COVID-19 became a much worse worldwide pandemic. SARS CoV-2, another coronavirus, causes it. Finding effective therapeutics against this global health crisis became a significant challenge for researchers. However, Allopathic medicine is effective to some extent with severe side effects, which cause concern. In this process, some researchers focused on natural compounds like plant-synthesized secondary metabolites (PSMs) for the treatment of COVID-19. Because these natural compounds like PSMs had a history of tackling a wide range of viral pathogens successfully without significant side effects. Many medicinal plants from different families have antiviral activities. This review intends to systematically evaluate the natural metabolites that could be used against this new disease looking at their natural sources, mechanism of action, and previous pharmacological usages. So, it can be a good initiation for the greater goal of finding effective natural therapeutics for the treatment of Covid-19 without any severe side effects.