3-Aminopropylphosphinic acid, also known in the literature as 3-APPA or CGP 27492, is a compound used in scientific research which acts as an agonist at the GABA<sub>B</sub> receptor. It is part of a class of phosphinic acid GABA<sub>B</sub> agonists, which also includes SKF-97,541. It has a binding affinity (pK<sub>i</sub>) to the GABA<sub>B</sub> receptor of 8.30 (i.e., ~3 nM).