Hydromel
From Tardis Wiki, the free Doctor Who reference
Hydromel was a vaccine used by the Vanir to stave off Lazar's disease. Hydromel was an organic compound, green and phosphorescent in appearance, which was inserted in the Vanir's armour to protect them from infection from the disease. The Vanir needed constant supplies in order to replace the depleted Hydromel, which became yellow and lost its phosphorescence when used up.
The corporation that the Vanir were enslaved by used the Hydromel in order to keep them working at Terminus, since they would cut off their supplies if they stopped obeying. (DW: Terminus)