Frequently Asked Questions Live Chat and Frequently Asked Questions are available for this Product. Biochem/physiol Actions Vorinostat or suberoylanilide hydroxamic acid (SAHA) is a potent, reversible pan-histone deacetylase (HDAC) inhibitor. It inhibits both class I and class II HDACs, altering gene transcription and inducing cell cycle arrest and/or apoptosis in a wide variety of transformed cells.