Equally illicit fentanyl and carfentanil are incredibly harmful opioids that may bring on a quick overdose and Dying when abused, but carfentanil is much more strong than fentanyl. Several doses from the anti-overdose drug naloxone (Narcan) is probably not effective to reverse an overdose. Keep on studyingRe: Definitely Freaked Out!! Fentanyl OD or