Solid supports for use in solid-phase peptide synthesis (SPPS) are provided. The solid supports may include a resin and a protected linker coupled to the resin. The linker may be an N-mercaptoethoxyglycine, an N-mercaptopropoxyglycine, an N-mercaptobutoxyglycine, and/or another suitable linker. Kits for use in SPPS are also provided. The kits may include a solid support, a solution including a thiol or a selenol, one or more pluralities of protected amino acids, and/or a wash buffer. Methods of SPPS are also provided. The methods may include providing a solid support including a resin coupled to a protected linker.