ओपिओइड्स के उपयोग से, तुरंत होने वाले और लंबे समय में होने वाले, दोनों तरह के लक्षण होते हैं। Semi-synthetic opioids are chemical substances derived from opiates. Synthetic opioids are chemicals created in labs. The term endogenous opioid usually refers to endorphins, which are chemical compounds designed in the body. http://highies.com