Fentanyl is a synthetic (lab-made) opioid that is estimated to be about 50–100 times stronger than morphine.(Source) It works by binding to opioid receptors in the brain and spinal cord to reduce the perception of pain.

In medical settings, fentanyl may be prescribed for:

• Severe post-surgical pain
• Breakthrough cancer pain
• Severe chronic pain that has not responded to other opioids

Common prescription forms of fentanyl include:

• Transdermal patches (applied to the skin)
• Lozenges or lollipops
• Sublingual tablets and films (dissolved under the tongue)
• Nasal sprays
• Injectable formulations used in hospitals and surgical centers

When prescribed, fentanyl is carefully dosed and monitored by a healthcare professional. However, illegally manufactured fentanyl—often made in clandestine labs and trafficked into the U.S.—is now widely found in the illicit drug supply.(Source) It may be sold as a powder, pressed into counterfeit pills that look like prescription medications, or mixed into heroin, cocaine, methamphetamine, or other drugs without the user’s knowledge.(Source)

Because fentanyl is so potent, even a very small amount can cause a life-threatening overdose, especially in people who do not regularly use opioids.(Source)