The rise of synthetic opioids has transformed the landscape of the opioid crisis, with fentanyl and carfentanil leading to alarming increases in overdose deaths. These drugs, though similar in origin, differ drastically in potency and risk. While fentanyl is widely known for its medical use and misuse, carfentanil is far deadlier, with even the smallest trace posing a lethal threat. Learning the difference between carfentanil and fentanyl is essential to understanding their dangers and preventing further tragedies.