Symbiote poison

From SGCommand

The symbiote poison is a poison designed to attack Goa'uld and Tok'ra symbiotes. Composed of two liquids, when mixed together, they cause almost instantaneous death to the symbiote. While not fatal outright to the host, the dying symbiote will automatically release a toxin into their host, killing it. The Tok'ra developed it to attack the System Lords while the Goa'uld Empire was in chaos following the deaths of Apophis and Cronus, but they were forced to abandon it when they learned that Anubis was alive. Later, the Trust used it to attack Goa'uld worlds by firing missiles filled with the gas through the Stargate, which they had recently stolen. SG-1 was able to reacquire the Stargate, but the al'kesh it was on fled to hyperspace, taking the symbiote poison with it. Later, Ba'al used it to kill all but three of his clones: the three that survived were one that was killed by Mitchell, a symbiote clone that was implanted into Adria, removed by the Tok'ra and presumably killed and another one that was captured by the Tau'ri and turned over to the Tok'ra for symbiote extraction, killing the last Ba'al and leaving the clone host as all that was left of him. (SG1: "Summit", "Last Stand", "Covenant", "Endgame", "Dominion", "Stargate Continuum")