Opioids are chemicals or drugs that act on a specific part of the brain called opioid receptors. Our bodies actually produce a small amount of natural opioids that bind to those receptors to help us deal with pain and calm us down. Prescription opioids bind to these same receptors. They were intended to help with severe or chronic pain, but they can also produce a heightened sense of pleasure or euphoria for some people.
Original opioids like morphine were made from the poppy plant, but now many prescription opioids are synthetic versions that have been developed. Some of the common opioids include hydrocodone (Vicodin), oxycodone (OxyContin or Percocet), oxymorphone (Opana), morphine (Kadian or Avinza), codeine and fentanyl.