What is Fentanyl?
Fentanyl is a synthetic opioid with extreme potency that can be legally prescribed for pain but is also commonly illegally made. It is about 50 times stronger than heroin and 100 times stronger than morphine.*
Because of its intense potency, very small amounts — 2 milligrams — can be lethal; this is equivalent to only a couple grains of salt or the tip of a pencil.*
Lethal Amount
* Fentanyl: One pill kills (no date) Texas Health and Human Services. Available at: https://www.hhs.texas.gov/services/mental-health-substance-use/mental-health-substance-use-resources/fentanyl-one-pill-kills (Accessed: 18 December 2025).
The Two Main Types of Fentanyl
Pharmaceutical Fentanyl
Pharmaceutical fentanyl is legally prescribed by doctors to treat severe pain, mainly after surgeries or for patients with cancer. When used for strictly medical purposes, fentanyl can be a very effective pain reliever. This type of fentanyl is produced by licensed pharmaceutical companies under regulated conditions, allowing for it to have consistent purity and potency.
Illicitly Manufactured Fentanyl (IMF)
Illicitly manufactured fentanyl is produced illegally and is a major cause of accidental poisonings. Its production is not legal and not regulated, causing the potency and purity to be wildly inconsistent. IMF is often found mixed into counterfeit pills that are made to resemble real prescription medications; fentanyl is especially dangerous since people oftentimes don't even realize that they're taking it in potentially lethal dosages. Some pills are completely substituted or simply laced with fentanyl, but due to the extreme potency of it, even a small amount could be fatal to the average person. IMF is also frequently mixed with drugs like heroin, cocaine, or methamphetamine in a powder, making it totally impossible to identify its presence. Though not as common, liquid fentanyl has also been found in some products like nasal sprays or eye drops.
** One pill can kill (no date) DEA. Available at: https://www.dea.gov/onepill (Accessed: 19 December 2025).