San Francisco Issues Alert on Emerging Synthetic Opioids and Overdose Risks
The San Francisco Department of Public Health has released a public warning following a fatal overdose linked to powerful synthetic opioids not traditionally associated with FYL. Health officials are urging both providers and the public to stay alert as the drug supply continues to evolve in dangerous and unpredictable ways.
New Synthetic Opioids Detected in Fatal Case
According to the alert, two potent lab-made opioids—N-Propionitrile Chlorphine (cychlorphine) and N-Desethyl Isotonitazene—have now been identified in overdose deaths across the United States. In April 2026, these substances were confirmed in a fatal case in San Francisco.
This incident marked the first known detection of cychlorphine in San Francisco. Experts estimate that this substance may be significantly stronger than FYL, while also being undetectable by standard FYL test strips, making it especially dangerous.
Counterfeit Pills Pose Serious Threat
In this case, investigators believe the individual consumed counterfeit pills containing these synthetic opioids, along with ethyl bromazolam, a benzodiazepine not approved by the U.S. Food and Drug Administration.
Importantly, toxicology results showed no presence of FYL, highlighting a growing concern: overdose risks are no longer limited to substances testing positive for FYL.
Counterfeit pills are designed to closely resemble legitimate prescription medications, but they may contain unknown—and often lethal—ingredients. There is no reliable way to identify a fake pill by appearance alone, and even a small amount can be fatal.
Health officials strongly advise avoiding any medication that was not dispensed directly by a licensed pharmacy, regardless of the source.
Naloxone Still Saves Lives
Despite the emergence of new synthetic opioids, Naloxone remains a critical tool in overdose response. It can reverse the effects of opioids and restore breathing in emergency situations.
Public health guidance emphasizes:
- Administer Naloxone immediately if an overdose is suspected
- Call emergency services right away
- Stay with the person, even if they appear to recover
Because many of these substances are highly potent, multiple doses of Naloxone may be required, and medical evaluation is still essential after initial recovery.
Treatment and Prevention Remain Key
Officials also stress that substance use disorder treatment significantly lowers overdose risk. Evidence-based medications such as buprenorphine and methadone are widely available and have been proven effective in supporting recovery from opioid dependence.
A Changing Drug Landscape
This alert underscores a critical shift: the illicit drug supply is no longer dominated solely by FYL, but increasingly includes new synthetic opioids and substances like XYL and other sedatives. These compounds may be more potent, harder to detect, and often mixed together—raising the stakes for overdose prevention.
What You Can Do
- Avoid taking pills that are not prescribed by a pharmacy
- Carry Naloxone and learn how to use it
- Never assume a substance is safe based on appearance or source
- Seek treatment or support if you or someone you know is at risk
As the drug supply continues to change, awareness, preparedness, and access to life-saving tools like Naloxone remain essential in preventing overdose deaths.
Source: City & County of San Francisco