The most potent illicit benzodiazepine tablets are more than 50 times stronger than the weakest, according to a new study by King’s College London. Analysing 100 illicit diazepam pills collected over a period of 25 years, researchers found that not only were some substantially stronger but many also contained ‘potentially harmful’ cutting agents.
Rates of recreational use of benzodiazepines like diazepam are continuing to rise, with the tablets often bought online. These are ‘frequently mislabelled’, says the report, with many containing wildly inconsistent doses and a diazepam content that has fluctuated over time according to external factors like the pandemic. The study – which was carried out in collaboration with TICTAC Communications and Nanalysis – analysed pills seized between 1998 and 2023 and found active content varying from 0.52mg to 26.25mg, while some samples contained ‘no detectable diazepam’.
The wide variability highlighted the need for ‘ongoing market monitoring and surveillance of emerging drug trends’, the researchers state. More than 300 deaths involving diazepam were recorded in England and Wales last year, according to the latest ONS figures, while EUDA’s most recent European drug report said that almost 90 new synthetic opioids had appeared on the European market since 2009, 20 of them nitazenes. Fake prescription drugs like benzodiazepine or oxycodone containing nitazenes were now ‘an increasing problem’, it said, raising concerns about them being used by a ‘broader range of consumers, including young people’.
The research showed that counterfeit diazepam tablets could be ‘highly unpredictable and dangerous’, said reader in bioanalysis at King’s, Dr Vincenzo Abbate. ‘While some tablets contained large amounts of diazepam, many didn’t contain any diazepam at all. This makes it very easy for people to accidentally take too much or mix harmful substances without knowing. By developing faster and more portable ways to test drugs, we hope to help reduce harm and keep people safer.’
Meanwhile, Myanmar’s opium cultivation has reached a ten-year peak, according to the latest UNODC survey. The 17 per cent increase – from 45,200 to 53,100 hectares – reaffirms the country’s role as the ‘world’s known main source of illicit opium following the continued decline of cultivation in Afghanistan’, the agency states. Cultivation in Afghanistan has fallen by another 20 per cent compared to last year, says UNODC, and now stands at just over 10,000 hectares – compared to more than 230,000 hectares before the Taliban’s 2022 cultivation ban, and fuelling fears of even more dangerous synthetic opioids entering the drug market to fill the gap.
Diazepam quantification in street tablets using benchtop 1H qNMR spectroscopy: Method validation and its application is published in the Quantitative NMR Journal and available here
Myanmar opium survey 2025: Cultivation, production and implications available here