How long does haldol (haloperidol) stay in your system?

Days: The half life of Haldol (haloperidol) is around 24 hours and after 5 half-lives the drug should be 99% out of your system. That means about 5 days, maybe a week at most.

7.5 days to 6 months: The half-life of Haldol (haloperidol) can vary from 1.5 days to more than 30 days, especially in those taking Haldol (haloperidol) decanoate, the long acting injectable form, once a month. It takes 4-5 half-lives to remove 94-97% of the drug concentration from the bloodstream. Therefore, it may take 7 1/2 days to 5 months or longer to remove it from the system.