[5]. The VSC enhancing effect will saturate with an increasing light-matter coupling strength η c (or Rabi splitting Ω R ), such that k 1 k 2 , k 3 , which breaks the mechanistic assumption that based on steady-state approximation. Related to this, for two chemically similar reactions, if one satisfies k 1 k 2 , k 3 but the other does not, then the current theory predicts that there will be a VSC effect for the first reaction but not for the second one.