Hydrophobic ligands usually bind to
Hydrophilic ligands cannot cross the plasma membrane and therefore bind cell-surface receptors that transmit the signal into the cell. Hydrophobic ligands such as steroid hormones readily diffuse across the bilayer and bind intracellular receptors that often function as ligand-activated transcription factors. This physicochemical distinction dictates the location and primary mechanism of receptor action.
Ref: NCERT Biology Class 11–12 Alberts et al Molecular Biology of the Cell Lodish et al, Molecular Cell Biology Cooper & Hausman, The Cell Abbas et al., Cellular and Molecular Immunology (for immunology sections)