The intracellular receptors are proteins found on the interior (inside the cytoplam or nucleus) of the cell, their ligands are on most cases small hydrophobic molecules, because they need to be able to cross the membrane ti reach their receptors, like the case of stradiol and testosterone. When the ligands binds to the receptors, these receptors change their shape to allow the interation between the molecules and provide the signaling to the rest of the cell.