The main protease, SARS-CoV-2 Mpro, is a cysteine protease that is essential for processing the polyproteins that are translated from the coronavirus RNA [108]. The substrate binding site of the enzyme is a cleft flanked by Gln189, Met49, Pro168, Glu166 and His41; the active site is Cys145 and His41. The compound with the best normalized docking score to SARS-CoV-2 Mpro was the sesquiterpene hydrocarbon (E)-β-farnesene (DSnorm = −115.4 kJ/mol). Other essential oil components showing good docking scores with SARS-CoV-2 Mpro were (E,E)-α-farnesene (DSnorm = −115.0 kJ/mol), (E,E)-farnesol (DSnorm = −112.4 kJ/mol), and (E)-nerolidol (DSnorm = −110.7 kJ/mol). The sesquiterpene hydrocarbons (E,E)-α-farnesene and (E)-β-farnesene occupy the substrate binding site, flanked by Gln189, Arg188, Met165, His41, and Asp 187 (Figure 1). The lowest-energy docked poses of both (E,E)-farnesol and (E)-nerolidol showed hydrogen bonding of the alcohol moiety to Gln192 and Thr190 and, in the case of (E)-nerolidol, also with GLN189 and ARG188 (Figure 2).