Cis-3-Aminocyclobutanecarboxylic acid (cis-3-ACBC) is a conformationally constrained, non-proteinogenic amino acid featuring a cyclobutane ring. This structural motif imparts rigidity and specific spatial geometry, making it a valuable scaffold in medicinal chemistry. It is a key intermediate in the synthesis of various pharmaceutical compounds. Its primary application is as a crucial building block for the development of novel drug candidates. It serves as a core structure for gamma-aminobutyric acid (GABA) analogues and other bioactive molecules targeting the central nervous system. Researchers utilize it to create conformationally restricted peptides and peptidomimetics, which can enhance metabolic stability and receptor selectivity compared to their linear counterparts. As a bifunctional molecule containing both an amine and a carboxylic acid, it is also employed in organic synthesis for constructing more complex heterocyclic systems and as a precursor for specialized ligands. Its unique strained-ring structure continues to be explored for applications in drug discovery programs focused on neurological disorders and beyond.