Carfentanil Situation Summary

Carfentanil has been found in the U.S. illegal drug supply

Carfentanil is a synthetic opioid. It is a fentanyl analogA up to 100 times more potent than fentanyl.1Because of its potency, even small amounts can increase the risk of overdose.

Exposure to carfentanil can cause trouble breathing. The symptoms of carfentanil overdose are the same as other opioids. Symptoms include:2

• Respiratory depression or arrest
• Drowsiness
• Disorientation
• Sedation
• Pinpoint pupils
• Clammy skin

Carfentanil has caused severe localized overdose outbreaks in the past but almost disappeared during 2021–2022.3Beginning in 2023, detection of carfentanil among overdose deaths increased. It is still rarely found in the U.S. illegal drug supply.

Carfentanil can spread quickly in the illegal drug supply and contribute to overdose outbreaks in communities and regions. This page will be updated every six months with the latest information on detection of carfentanil.

How CDC tracks carfentanil

• Exposure to carfentanil: People’s exposure to carfentanil is measured by tracking detection of carfentanil in urine drug tests conducted by Millennium Health. Specimens come from adult patients in the care of clinicians in behavioral health, primary care, substance use treatment, or other patient care settings. Carfentanil is tested in all specimens that test positive for fentanyl. This information can help monitor changes in exposure to carfentanil.
• Carfentanil detection among drug overdose deaths: Detection is captured by the State Unintentional Drug Overdose Reporting System (SUDORS), which collects full postmortem toxicology testing for unintentional and undetermined intent overdose deaths in funded jurisdictions. This information helps track carfentanil involvement in overdose deaths.
• Carfentanil in the illegal drug supply: Comprehensive testing of illegal drug product and paraphernalia samples is conducted by 18 local public health departments and shared quarterly with CDC. Results from 15 jurisdictions with full data are reported. Results can provide early warning of increases in carfentanil in the drug supply.
  

More information on these data sources is provided in the page footnotes.BCD

Carfentanil detection is rare but has increased since 2023 across the U.S.

Figure 1: Trends in the percentage of fentanyl-positive urine specimens testing positive for carfentanilB & trends in the percentage of overdose deaths with carfentanil detectedCJanuary 2023–June 2026

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• Among fentanyl-positive specimens, the percentage of urine drug specimens testing positive for carfentanil increased from 2023 to 2025.
  • A peak was observed during July–September 2025, when 1.73% of fentanyl-positive specimens tested positive for carfentanil, followed by a decline.
• The percentage of overdose deaths with carfentanil detected increased in a similar pattern. Detection increased from 0.02% of deaths during January–March 2023 to 3.20% during July–September 2025, followed by a decline.

Figure 2: Trends in the percentage of fentanyl-positive urine specimens testing positive for carfentanilB by U.S. Census Region, January 2023–June 2026

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• Sharper increases in carfentanil detection among fentanyl-positive specimens were seen in the Midwest census region beginning in 2025. Detection across all regions decreased from July–September 2025 to January–March 2026.
• Detection increased slightly from January–March to April–June 2026 in the Midwest, Northeast, and West.

Figure 3: Number of jurisdictions detecting carfentanil in opioid-positive drug product and paraphernalia samples across 15 sentinel sitesDJanuary 2025–June 2026

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• Carfentanil was detected in illegal opioid samples in 12 out of 15 jurisdictions during January–June 2025, 13 during July–December 2025, and 9 during January–June 2026.
• From January–June 2025 to July–December 2025, the number of jurisdictions with carfentanil in 5% or more of illegal opioid samples increased from two to four.
• During July–December 2025, all four jurisdictions with carfentanil in 5% or more of illegal opioid samples were in the Midwest and Northeast.
  

What to do if someone is having an overdose from carfentanil

It may be hard to tell whether a person is high or experiencing an overdose. If you aren't sure, treat it like an overdose—you could save a life.

Because of carfentanil's potency, multiple doses of an opioid overdose reversal medication such as naloxone or additional medical care might be required to reverse or treat an overdose.4

*Naloxone is a life-saving medication that can reverse the effects of opioid overdose and save lives. It is available in all 50 states and over the counter - you don't need a prescription.

** Most states have laws that may protect a person who is overdosing or the person who called for help from criminal penalties.

What CDC is doing

CDC supports states and local communities working to detect, prevent, and respond to health threats – including emerging threats like carfentanil in the drug supply. CDC's Overdose Data to Action (OD2A) program supports 49 states and Washington, D.C. to collect and report detailed information about all unintentional and undetermined intent drug overdose deaths to the State Unintentional Drug Overdose Reporting System (SUDORS). This includes full postmortem toxicology testing results, which can identify the presence of carfentanil among overdose deaths.

Local health departments conduct laboratory testing of illegal drug product and paraphernalia samples through OD2A or through testing by the National Institute of Standards and Technology (NIST).

Suggested citation

Centers for Disease Control and Prevention. Carfentanil Situation Summary. Atlanta, GA: US Department of Health and Human Services, CDC; [INSERT YEAR, MONTH, DAY]. Access at: www.cdc.gov/overdose-prevention/situation-summary/carfentanil.html