Fentanyl is an extremely potent drug used to treat severe pain. Fentanyl is a synthetic (artificially created) opioid. Opioids are drugs that are derived from opium or that have a chemical structure similar to drugs derived from opium. Fentanyl produces effects like those of the opioids heroin and morphine. But fentanyl is much stronger than heroin or morphine. A 2-milligram dose of fentanyl, equivalent in size to a few grains of sand, can kill a person.
Fentanyl is prescribed to treat breakthrough pain, usually in cancer patients. Breakthrough pain is a sudden flare of intense pain that occurs despite regular pain treatment. Fentanyl can also be used as an anesthetic (pain-dulling drug) in patients undergoing delicate operations, such as heart surgery. Legally prescribed fentanyl is taken as an injection, as a patch applied to the skin, or orally as a pill or lollipop.
Fentanyl binds to structures called opioid receptors in the brain, causing cells to release the chemical dopamine. The release of dopamine causes a brief, intense sensation of relaxation that can bring a sense of euphoria (well-being), temporarily dulling intense pain and easing suffering. Fentanyl can be addictive, especially with prolonged use. Overuse can cause seizures and result in death.
Fentanyl was developed in 1959 by the pharmaceutical company Janssen Pharmaceutica. It was introduced in the United States in the 1960’s as an anesthetic. It is approved by the U.S. Drug Enforcement Administration for use in pain management and anesthesia. The drug’s trade names include Actiq, Duragesic, and Sublimaze, among others. Fentanyl is generally not recommended for patients under the age of 18.
Fentanyl is a widely misused drug. It mimics the effects of heroin but is about 50 times more powerful. Manufacturers of illegal drugs purposely contaminate heroin and other drugs with fentanyl to increase their potency. They also manufacture counterfeit (fake) pills. These pills resemble legitimate prescription drugs, but they contain fentanyl instead of the imitated drug, or in addition to the imitated drug. 
In the United States, the illegal manufacture and distribution of fentanyl has caused a major public health crisis. Many people take illegal drugs without knowing how much fentanyl they contain. They may not know the drugs contain fentanyl at all. As a result, deaths from fentanyl overdose are common.
Fentanyl has been misused since the 1970’s, but overdose deaths from fentanyl increased dramatically during the 2000’s. By the late 2010’s, more overdose deaths were caused by fentanyl and other synthetic opioids than by any other type of drug.
