Sieber amide resin has been developed for the Fmoc-SPPS of fully t-butyl protected peptide amides. Cleavage can be achieved with 1% TFA in methylene chloride. Scavengers may be required. As N-methylation increases the acid-lability of the peptide bond, Malakoutikhah et al. employed Sieber resin for obtaining short peptide amides containing multiple MePhe residues.