In our recent publication in Nature Communications, we reveal the complex relationship between molecular isomerization kinetics, dihedral friction, and solvent viscosity in viscogenic solvent environments. We demonstrate that deviations from a linear dependence of isomerization rates on solvent viscosity, typically attributed to internal friction effects, are actually due to the simultaneous violation of both the Stokes-Einstein relation for dihedral dynamics and Kramers’ theory for isomerization kinetics. Such a detailed decomposition of internal friction effects has not been previously possible due to the difficulties associated with calculating one critical quantity: friction.