Both equally illicit fentanyl and carfentanil are really hazardous opioids that may lead to a quick overdose and Dying when abused, but carfentanil is much more potent than fentanyl. Many doses on the anti-overdose drug naloxone (Narcan) is probably not effective to reverse an overdose. Keep on readingFentanyl For Sale Online. Fentanyl For Sale is