Illicitly manufactured fentanyl is becoming a major driver of opioid overdose. According to the Centers for Disease Control and Prevention (CDC), illegal, lab-made fentanyl was involved in more than 50% of opioid overdose deaths in 2016. A new application note discusses the analyses of fentanyl using FT-Raman spectroscopy along with the advantages that this technique offers for the detection and identification of illicit drugs.