Bioregulator and Neuropeptides
Most of this class is very short, two to four residues, which puts it at the low end of the molecular weight range and makes net peptide content a larger share of the question than it is elsewhere. On a short sequence the counterion can account for a meaningful fraction of the gross weight.
The neuropeptide entries here are longer and carry N-terminal or C-terminal extensions to the parent sequence. Structurally they have little in common with the short bioregulators beyond both being unmodified linear chains, so read the sequence on the certificate rather than assuming from the category.
Related classes: Single-Chain Research Peptides, Melanocortin Research Peptides.
Certificates of analysis for every lot on this site are listed in the certificate of analysis library.