When it comes to carfentanil vs. fentanyl, the question of which opioid is more dangerous often comes up. Both are powerful synthetic opioids that have contributed to the ongoing synthetic opioid crisis in the United States. While fentanyl is deadly, carfentanil is even more potent, making it one of the most dangerous synthetic opioids. In this article, we will look at the differences in carfentanil potency, how each drug works, and their fentanyl risks.