"Cannibals are a horrifying example of what happens when one loses all sanity. Remember to stock up on Thorazine." -Loading Screen
Thorazine is the trade name of Chlorpromazine, a powerful anti-psychotic drug used in the treatment of mental disorders such as schizophrenia.
Overview
Thorazine is an effective treatment against the deterioration of mental health caused by conditions in the wasteland. Compared to alcohol, Thorazine restores a much greater amount of sanity and carries no risk of addiction, the downside being that it is fairly rare and can only be obtained at great personal risk, usually necessitating mass-murder and a large loss of sanity. Most Thorazine found in the Mojave is carried by NCR expeditionary forces or located in NCR medical caches (Though the Divide tribals also carry it in abundance). A single dose of Thorazine restores 100 points of sanity.
Trivia
Though the depiction of Thorazine in DUST has it as non-addictive, the issue of dependency associated with Chlorpromazine remains a point of contention among medical professionals.
The forecaster refers to Thorazine being injected via hypodermic syringe. While this is definitely possible, most real-world preparations of Thorazine are administered orally. This, and its possession by NCR personnel suggests that the NCR has resumed production of the drug in its territory, using injection as the standard delivery system.