Scientist are more interested in the feeling of numbness caused by capsaicin. By pouring capsaicin into surgically exposed nerves, the affected areas should remain numb for several days. This means less pain after major surgery. It also means the patient will have to take less opiate painkillers. Opiates are notorious for causing side effects, including drowsiness, nausea, vomiting, dilated pupil, euphoria, constipation and respiratory depression.