Isoniazid also known as isonicotinylhydrazide (INH) is an antibiotic used as a first-line agent for the prevention and treatment of both latent and active tuberculosis.

For R&D use onlynot for drug household or other uses.

Isoniazid was first made in the early 20th century but its activity against tuberculosis was first reported in the early 1950s. Three pharmaceutical companies unsuccessfully attempted to patent the drug at the same time the most prominent one being Roche which launched its version Rimifon in 1952.