¹³ C and ¹⁵ N Benchtop NMR Detection of Metabolites via Relayed Hyperpolarization**

Abstract Parahydrogen‐based nuclear spin hyperpolarization allows various magnetic‐resonance applications, and it is particularly attractive because of its technical simplicity, low cost, ability to quickly (in seconds) produce large volumes hyperpolarized material. Although many parahydrogen‐based techniques have emerged, some them remain unexplored due the lack careful optimization studies. In this work, we investigate optimize a novel parahydrogen‐induced polarization (PHIP) technique that relies on proton exchange referred below as PHIP‐relay. An INEPT (insensitive nuclei enhanced by transfer) sequence employed transfer from protons heteronuclei ( N C) signals are detected using benchtop NMR spectrometers (1 T 1.4 T, respectively). We demonstrate applicability PHIP‐relay for wide range biochemicals examining such key metabolites urea, ammonium, glucose, amino acid glycine, drug precursor benzamide. By optimizing chemical parameters PHIP‐relay, achieve 17,100‐fold enhancement signal [ C, ]‐urea compared thermal measured at 1 T. also show repeated measurements with shorter exposure parahydrogen provide higher effective signal‐to‐noise ratio longer bubbling.