How long does a benztropine high take?

Cogentin (benztropine) high. Delirium caused by too much Cogentin (benztropine) is very unpleasant experience, along with blurred vision & drying effect.
More than prescribed. I wonder why you are asking this, are you trying to have hallucinations? The usual maximum dose of benztropine is six mgs per day. Any amount over that is unsafe. The hallucinations caused by too much benztropine can be associated with other dangerous effects.