Parahydrogen-induced polarization (PHIP) is a class of hyperpolarization techniques which deliver spin polarization to a sample by way of a nuclear spin isomer of the hydrogen molecule, namely parahydrogen, characterized by zero total nuclear spin of the two hydrogen atoms. Para-enriched hydrogen (p-H2) can be generated by cooling hydrogen gas in the presence of a paramagnetic material . In PHIP, the singlet spin order of parahydrogen can be converted into enhanced (nonequilibrium) nuclear magnetization of the hydrogenation product if p-H2 is added in a pairwise manner to an unsaturated precursor using a suitable hydrogenation catalyst . Spin-polarization levels of a few to a few tens of % can be achieved with PHIP depending on experimental implementation . In ZULF NMR experiments, enhanced signals can be observed if there is a heteronuclear spin present in the molecule which renders the parahydrogen-derived protons magnetically inequivalent .