The opioid crisis continues to hold the world in a dangerous grip. What often begins as a harmless injury requiring painkillers to support healing can lead to severe addiction, fueled by the abundance of drugs offered on the unregulated market.
Fentanyl, one of the most powerful synthetic opioids, is routinely misused for unregulated recreational use—whether intentional or not—accounting for about 70 percent of all overdose deaths between 2021 and 2024 in the United States, according to the Centers for Disease Control (CDC).
Now a new and potentially dangerous drug has entered the market: cyclorphine. This designer substance, also a synthetic opioid, was found in three collected opioid samples in Toronto in October 2025. What worries officials about this discovery is that its effects on the human body are still unknown. Early pharmacological analysis has shown that it has a potency similar to fentanyl, making it a dangerous addition to the already insidious illegal drug market.
Read more: Female hormones help the body produce its own opioids, which help cope with pain.
New Opioid Found During Community Drug Test
Some communities offer drug testing services—tools that allow people to find out what's actually in their drugs without fear of legal repercussions—and also help authorities monitor what's circulating in the local market.
One such service in Toronto found cyclorphine in three opioid samples through on-site analysis using gold standard technologies.
According to their report, the samples were supposed to contain hydromorphone (trade name Dilaudid), oxycodone (brand name Oxycontin) and Percocet, a combination of oxycodone and acetaminophen. However, they consisted entirely of cyclorphine, and not the drugs they were supposed to be.
What do we know about cyclorphine?
According to the Toronto Drug Testing Service, cyclorphine is a synthetic opioid of unknown strength and effect. Synthetic opioids are entirely man-made and can be significantly more powerful than naturally occurring opioids such as morphine, unfortunately leading to a higher potential for addiction and overdose.
This is why synthetic opioids follow strict prescription guidelines to reduce unwanted side effects and prevent illicit distribution in substance abuse cases.
To circumvent prohibitions and other legal controls on specific synthetic opioids, illicit manufacturers often alter the chemical structure to create new substances that are marketed as well-known prescription pills. Several new synthetic opioids, including cyclorphine, have been reported for the first time in Europe and the United States since 2024, putting public health and law enforcement authorities on high alert, according to the United Nations Office on Drugs and Crime (UNODC) and the Center for Forensic Sciences Research and Education (CFSRE).
The strength and effects of cyclorphine are unknown
No one yet knows the exact effectiveness or side effects of cyclorphine, making it extremely difficult to assess the real risk. Like fentanylwhich is often unknowingly added to other illicit substances to increase their addictive potential, users may not even realize they are consuming this new synthetic opioid.
Experts say that in the event of an overdose, naloxone, an opioid antagonist, should reverse the effects of cyclorphine, like other synthetic opioids.
Although detection remains rare, authorities continue to monitor unregulated drug supplies and educate the public about cyclorphine and how this trend is developing.
This article does not contain medical advice and should be used for informational purposes only.
Read more: Here's what makes some opioids more deadly than others
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