Parafluorofentanyl (commonly referred to as 4-fluorofentanyl or pFF) is an opioid analgesic analog with its origins dating back to the 1960s, when Janssen Pharmaceuticals developed it.
During the early 1980s, 4-Fluorofentanyl made a brief appearance on the US black market, a period marked by a lack of citation records. However, this was before the introduction of the Federal Analog Act, which represented a groundbreaking shift in drug regulation. This act, for the first time, aimed to control entire drug families based on structural similarities rather than scheduling each drug individually as they emerged. Notably, the synthesis of 4-Fluorofentanyl shares the same chemical route as fentanyl, but it replaces aniline with para-fluoro aniline in the synthetic process.
The side effects associated with fentanyl analogs closely resemble those of fentanyl itself, encompassing symptoms like itching, nausea, and the potential for severe respiratory depression. This condition can pose a life-threatening risk. Fentanyl analogs have tragically claimed the lives of thousands across Europe and the former Soviet republics, particularly since the resurgence in their use that began in Estonia in the early 2000s. Furthermore, novel derivatives of these substances continue to surface, perpetuating this public health concern.
In 2020, the Drug Enforcement Agency (DEA) issued a warning about the growing prevalence of parafluorofentanyl in Arizona, underlining the need for heightened vigilance and awareness surrounding this potent synthetic opioid.

IUPAC name
CAS Number90736-23-5 
PubChem CID62300
CompTox Dashboard (EPA)DTXSID0048929
Chemical and physical data
Molar mass354.469 g·mol−1


1. What is Parafluorofentanyl (pFF)?

Parafluorofentanyl, often abbreviated as pFF or 4-fluorofentanyl, is a synthetic opioid analgesic that belongs to the fentanyl family. It was initially developed by Janssen Pharmaceuticals in the 1960s.

2. How is Parafluorofentanyl used?

Parafluorofentanyl is typically used in powder or crystalline form. It can be consumed through various routes, including oral ingestion, nasal inhalation, or intravenous injection. However, its use is dangerous and illegal in many places.

3. What are the effects of Parafluorofentanyl?

The effects of Parafluorofentanyl are similar to those of fentanyl, including potent pain relief and euphoria. However, it also carries serious risks, such as potential respiratory depression, which can be life-threatening. Users may experience side effects like itching and nausea.

4. Is Parafluorofentanyl legal?

The legality of Parafluorofentanyl varies by country and region. In many places, it is classified as a controlled substance, making it illegal to manufacture, distribute, or possess. It is essential to check local laws and regulations regarding this substance.

5. Is Parafluorofentanyl safe to use?

No, Parafluorofentanyl is not safe for recreational or medicinal use. It is a potent opioid and carries a high risk of overdose and severe adverse effects, including death. Using this substance is strongly discouraged.

6. Can Parafluorofentanyl be addictive?

Yes, like other opioids, Parafluorofentanyl has the potential for addiction and physical dependence. Using it can lead to the development of tolerance and withdrawal symptoms when attempting to quit.

7. What are the potential dangers of Parafluorofentanyl?

The dangers associated with Parafluorofentanyl use include the risk of overdose, respiratory depression, and death. Additionally, it may contain impurities or be mixed with other harmful substances, further increasing the dangers of its consumption.

8. Are there any medical uses for Parafluorofentanyl?

No, Parafluorofentanyl is not approved for any medical or therapeutic purposes. It is strictly intended for scientific research and should not be used outside of a controlled laboratory setting.

9. How can I get help if I or someone I know is struggling with Parafluorofentanyl addiction?

If you or someone you know is dealing with substance abuse or addiction related to Parafluorofentanyl or any other opioid, it is crucial to seek professional help. Contact local addiction treatment centers, medical professionals, or addiction hotlines for guidance and support.

10. What steps can be taken to prevent Parafluorofentanyl-related harm?

Preventing harm associated with Parafluorofentanyl involves education, awareness, and strict adherence to legal regulations. Avoid using this substance, and encourage others to do the same. Promote responsible drug use and seek assistance for addiction or substance abuse issues promptly.


  1. US Patent 3164600 – A Journey into Innovation US Patent 3164600 represents a significant milestone in the realm of intellectual property, reflecting groundbreaking innovations.
  2. Designer Drugs: A Historical Perspective and Future Outlook In March 1988, Henderson GL published an insightful article titled “Designer Drugs: Past History and Future Prospects” in the Journal of Forensic Sciences. The work delves into the history and potential developments in the world of designer drugs.
  3. Exploring Opioid Receptor Interactions Ulens, Van Boven, Daenens, and Tytgat’s research in September 2000 took a deep dive into the interaction of p-fluorofentanyl with cloned human opioid receptors. Their work explored the roles of Trp-318 and His-319 in mu-opioid receptor selectivity, providing valuable insights into this area of pharmacology.
  4. Fentanyls in Europe: A Growing Concern In July 2015, Mounteney, Giraudon, Denissov, and Griffiths addressed the alarming rise of fentanyls in Europe in their article, “Fentanyls: Are We Missing the Signs? Highly Potent and on the Rise in Europe.” The study highlights the need for heightened vigilance and control measures.
  5. DEA’s Warning about a Newly Encountered Fentanyl-Like Substance On December 28, 2020, KNXV reported that the Drug Enforcement Administration (DEA) issued a warning about a newly encountered fentanyl-like substance in Arizona, emphasizing the urgency of addressing this public health concern.
  6. DEA Alert: ‘Extremely Dangerous’ Form of Fentanyl, on December 29, 2020, further emphasized the DEA’s alert regarding an ‘extremely dangerous’ form of fentanyl. This warning underscores the critical need for awareness and intervention to combat the dangers associated with these substances.

Leave a Comment

Your email address will not be published. Required fields are marked *