All BetterBio Synthesis educational content is provided for research and informational purposes only. Peptides and related materials discussed here are intended for Research Use Only and are not for human consumption, not for clinical use, and not intended to diagnose, treat, cure, or prevent any disease. This article is not medical advice.

Peptides are often described by their amino acid sequence, but sequence alone is not always the complete identity of a research peptide. The ends of the molecule matter too.

Every linear peptide has two termini: an N-terminus at the amino end and a C-terminus at the carboxyl end. Those ends can be left in their default chemical state, or they can be intentionally modified. Two of the most common terminal modifications are N-terminal acetylation and C-terminal amidation.

For BetterBio-style peptide education, this topic connects basic peptide chemistry with COA literacy. A peptide name can look familiar while the actual molecule differs at one or both termini. That difference can affect molecular weight, chromatographic retention, mass spectrometry confirmation, degradation pathways, and biological context.