There is no evidence that Viagra can cure COVID. More research needs to be done to determine that it is a viable treatment for the infection.
A study published by the National Center for Biotechnology Information, titled 'Hypothesis of COVID-19 Therapy with Sildenafil,' proposed using sildenafil to reduce the production of inflammatory cascade and thromboembolism caused by COVID-19. However, the study is yet to be peer-reviewed.
Another study conducted by the U.S. National Library of Medicine didn't find any "statistically significant differences in the oxygenation parameters of COVID patients who were either given sildenafil or a placebo." The study concluded that sildenafil treatment could have a "potential therapeutic role regarding the need for Invasive Mechanical Ventilation" in COVID-19 patients with specific perfusion patterns in subtraction computed tomography angiography (sCTA). However, a large-scale study is needed to confirm these results.
Scientists are currently working to identify if sildenafil can prevent or treat COVID-19.
Considering no direct impact of Viagra has been identified, more detailed studies are required to establish the benefits of the medicine in treating the COVID-19 infection. Thus, the claim that Viagra helps in curing COVID-19 is false.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19, including symptoms, prevention, and available treatment, please refer to the World Health Organization or your national healthcare authority.