In brief
- The Welsh service WEDINOS analyzed thousands of samples anonymously and free of charge between April 2025 and March 2026: 36.6% of community samples with a known purchase intent did not contain the expected substance.
- For the first time in this programme, “orphines”—a family of highly potent synthetic opioids—were identified mixed with veterinary sedatives in samples sold as heroin.
- 43% of vape products submitted as THC, CBD or cannabinoids contained synthetic cannabinoid receptor agonists; this is not an estimate of the whole market.
The Welsh public drug-checking program, WEDINOS (Welsh Emerging Drugs & Identification of Novel Substances), has published its annual report for the period of April 2025 to March 2026. The conclusion that has most resonated in the British press is simple: slightly more than one in three community samples with known purchase intent did not contain what was expected. The selected submissions cannot establish that proportion among all buyers.
What the testing service records
WEDINOS has been operating since 2013 and is managed by Public Health Wales. The anonymous service requires a Sample and Effects form and correct postcode information. The inspected pages do not guarantee acceptance from outside the United Kingdom or results within a fixed number of days. It is the same principle applied by harm reduction services in other countries: the more people check what they consume, the more accurate the map of the real market becomes, rather than the one advertised by those selling the substances.
Orphines where heroin was expected
The novelty of the report is the “orphines” (orphine analogues), high-potency synthetic opioid analogues identified by the programme as an emerging concern. The WEDINOS team detected them for the first time, mixed with veterinary sedatives in samples that the submitter believed to be heroin. Rick Lines, head of the program at Public Health Wales, summarizes it this way: the data “demonstrate once again the continued volatility of illicit drug markets and the high level of substitution within the market.” The report adds that nitazenes remain present and that newly synthesized benzodiazepines have appeared, sold as diazepam—another category where the actual content can differ significantly in potency from the drug it mimics.
What this implies
These WEDINOS samples cannot describe the entire Welsh market or directly compare it with Spain, and the release does not attribute its findings to a particular cause such as regulation or scarcity. Another archive article discusses cyanazenes, designed to evade the ban on nitazenes. For anyone planning to consume something purchased as an opioid, the standard harm reduction guidelines—starting with a minimal dose, not mixing with other depressants like alcohol or benzodiazepines, not using alone, and having naloxone on hand if possible—remain valid, with the caveat that the label “heroin” no longer guarantees knowledge of what is inside. The other finding in the report, that 43% of THC or CBD vapes contained undeclared synthetic cannabinoids, serves as a reminder that the problem of unknown composition is not limited to opioids: it also extends to products sold as legal and harmless.
Source
- Public Health Wales / NHS Wales. Powerful new synthetic opioids identified by Welsh drug testing programme reveals increasingly unpredictable illicit drug market. Public Health Wales, August 25, 2026.
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
