Which type of hormones do not enter the cell's plasma membrane and instead bind to receptors on the cell surface?

Peptide hormones are hydrophilic and consist of chains of amino acids. They cannot cross the lipid bilayer and instead bind to receptors on the cell surface, triggering a signaling cascade inside the cell.

Contrast this with other hormone types: Steroid hormones and Vitamin D hormones are lipophilic (fat-soluble) and can pass through the plasma membrane to bind to intracellular receptors. Thyroid hormones, although derived from amino acids, are also lipophilic and can cross the membrane.