Common side effects include severe anxiety, akathisia, sedation, dysphoria, insomnia, sexual dysfunction, low blood pressure, muscle stiffness, muscle pain, tremors, increased salivation, and
stuffy nose. Risperidone
has been associated with minimal to moderate weight gain, with one study finding that 26 to 38 percent of participants on the drug experienced weight gain.
Muscle striffness and pain along with anxiety can cause bad headache...