7-Nitroindazole is a non-selective inhibitor of NOS isoforms in vitro?for neuronal nitric oxide synthase showing a 10-fold selectivity for neuronal NOS.

NG-Nitroarginine methyl ester is a non-selective nitric oxide synthase inhibitor. It has been utilized experimentally to induce hypertension.

S-Methylisothiourea sulfate ((S)-Methylisothiourea sulfate) is a potent and selective inhibitor of iNOS and exerts beneficial effects in rodent models of septic shock.