Fentanyl: the synthetic opioid 50 times stronger than heroin that killed over 100,000 Americans in a single year
The synthetic opioid fentanyl, up to 100 times more potent than morphine, has caused the deadliest drug epidemic in US history, with over a million deaths in a decade. While fatalities are now falling, Italy is on alert after five deaths in 2025.
What is fentanyl
Fentanyl is a synthetic opioid first synthesised in 1959 by Belgian chemist Paul Janssen. It was developed as a fast-acting, potent analgesic and anaesthetic, and today it is used medically for severe chronic pain, especially in cancer patients, and during surgery. The World Health Organization lists it as an essential medicine for advanced cancer. However, its extreme potency (50 to 100 times that of morphine, and 30 to 50 times that of heroin) makes it highly dangerous outside controlled settings. As little as 2 milligrams can be lethal.
Just 2 milligrams can kill.
On the illicit market, fentanyl is sold as a powder, pressed into counterfeit pills, or mixed with heroin, cocaine and methamphetamine. Its low production cost and high potency have made it a lucrative product for traffickers, with clandestine labs mainly in Mexico.
The US epidemic
In the United States, fentanyl has fuelled the worst drug crisis in the country's history. Deaths from synthetic opioids doubled between 2019 and 2022, peaking at 107,941 total overdose fatalities that year. The drug earned the nickname "zombie drug" because users often appear catatonic, staggering or frozen in place, a condition worsened when fentanyl is combined with the veterinary sedative xylazine. The epidemic has cut across urban and rural areas, all social classes and age groups.
- Belgian chemist Paul Janssen synthesises fentanyl.
- Fentanyl is commercialised as an anaesthetic and analgesic.
- Illicit fentanyl begins appearing on the US market, often mixed with heroin.
- US synthetic opioid deaths double, peaking at 107,941 total overdose fatalities in 2022.
- Italy adopts a National Prevention Plan against improper use of fentanyl and other synthetic opioids.
- Italy records five fentanyl-related deaths.
- US overdose deaths continue to decline, with provisional data pointing to a further drop.
After the 2022 peak, overdose deaths began to fall. Provisional data show a drop of more than 35% between 2023 and 2024, with a further decline expected in 2026. Despite this progress, the cumulative toll exceeds one million lives lost over ten years.
Italy on alert
Italy has not experienced an epidemic on the US scale, but authorities are watchful. In 2025, five deaths were linked to fentanyl, either alone or in combination with other substances, according to the annual report on drug addiction presented to parliament in June 2026. The government adopted a National Prevention Plan against the improper use of fentanyl and other synthetic opioids in 2024. Experts warn that even a single theft from a hospital could open a breach, as the drug is legally stored in medical facilities.
It is normally used as a painkiller for the most severe forms of pain, such as chronic cancer pain.
Effects and antidote
Fentanyl binds to opioid receptors in the brain, blocking pain signals and producing euphoria, sedation and, at higher doses, severe respiratory depression. Overdose signs include coma, pinpoint pupils and dangerously slow breathing that can stop altogether. The antidote naloxone can rapidly reverse these effects, but because fentanyl's action often outlasts that of naloxone, multiple doses may be required. In Europe, pharmacies are obliged to stock naloxone.
