Procyclidine is also sometimes used for the treatment of dystonia (but not tardive dyskinesia), a rare disorder that causes abnormal muscle contraction, resulting in twisting postures of limbs, trunk, or face.

Side effects include nausea, constipation, urinary retention, blurred vision, anxiety, cognitive impairment, confusion, dizziness, gingivitis, hallucination, memory loss, rash and vomiting.

Other known symptoms of overdose are: clumsiness or unsteadiness, being severely drowsy, having a severely dry mouth, nose, or throat, having an altered mood or other mental changes, seizures, being short of breath or having troubled breathing, a dry and warm, flushed skin.

A suspected overdose with severe life-threatening symptoms should immediately be brought to medical attention, where reversal can be attempted with physostigmine administered intravenously or subcutaneously.

[2] Procyclidine, 1-cyclohexyl-1-phenyl-3-pyrrolidinopropan-1-ol, is synthesized in exactly the same manner as was seen for trihexyphenidyl, except this time the linear synthesis begins with the preparation of 3-(1-pyrrolidino)propiophenone.