Thuja occidentalis, also known as Arbor Vitae has been explored as a potential treatment for the influenza virus and the common cold (Naser et al., 2005). It has been used as a treatment for warts (Joseph et al., 2013). Some evidence exists for the treatment of PCOS as well (Akkol et al., 2015).

The general mechanism of action is understood to be its effect on causing tumor necrosis factor-mediated apoptosis. (Sunila et al., 2011). It has been used as prophylaxis in Europe for viral infections (Petrunov et al., 2007). Thuja is known to be cytotoxic to human melanoma and caused apoptosis without severely affecting host cells (Biswas et al., 2011)

In this instance, is it not appropriate to explore the potential of Thuja occidentalis in the prophylaxis of Covid-19?