The name Novichok is used for a number of chemical compounds that have been used as nerve agents (similar to nerve gas) from the 1970s to at least the 1990s in the Soviet Union. There are 3–5 different substances, all called Novichok. The exact formula of these agents is unknown. The following facts are known or likely:
- Novichok is produced by combining two (or more) other substances. Unless they are combined, these other substances are not dangerous; as an example: fertilizer for agriculture
- At least four or five compounds are known to exist.