The Zarn Corporation is a business in Star City that manufactures Revlextra.
When Oliver Queen called off the Bratva for his hit on Adrian Chase, Anatoly Knyazev still intended to get the drugs for which he came to Star City. The Bratva set up a heist on a Zarn Corporation warehouse which manufactured Revlextra which would be used to create an addictive street drug. Team Arrow intercepted the Bratva's heist causing a firefight in the warehouse. Oliver held Anatoly at gunpoint but shot an alarm instead causing both factions to run off from the warehouse.