Invisible Overdose: The Nitazene Crisis in the UK

Papers are the author’s own opinion and do not necessarily reflect the views of Onward.

Executive Summary

Since 2022, the UK has seen a significant increase in deaths linked to nitazenes – a class of illegal synthetic opioids which can be more potent than fentanyl and up to 500 times stronger than heroin. The Home Office says that nitazenes have been linked to over 750 deaths across the UK since June 2023.

Despite awareness of the presence of nitazenes in the UK drug supply and the increased number of related deaths, shortcomings in official statistics make it difficult to assess the true scale of the damage. There are also considerable inconsistencies across official estimations on nitazene-linked deaths. Whilst figures from the Office for National Statistics have led many to report that there were 195 nitazene-linked deaths in England and Wales in 2024, other official sources suggest they could have been higher, standing at 303 in England alone. These gaps and inconsistencies will make it difficult for health authorities to prepare and respond effectively to the problem.

Despite these issues, the details of overdose cases to date can tell us a lot. Nitazene consumption is often inadvertent. Variants have been found in substances from heroin to imitations of legally available medicines. Those at risk of overdosing on the substance include both long-term users of hard drugs and individuals self-medicating for conditions such as chronic pain and common mental health problems.

There are also notable sex-based and regional dynamics. The overdose death rate among men is roughly twice as high as that among women as regards all illegal drugs, and this rate appears to be even higher in relation to nitazenes, with available data suggesting that men could be more than five times as likely to overdose on this novel illicit opioid. Whereas the North typically has the highest fatal drug overdose rate, London has been disproportionately affected by nitazenes.

By developing an integrated national database of coroners’ and toxicology reports similar to that of Canada, the UK could build a more accurate picture of the scale of its nitazene problem.

This is the first of a two-part analysis of the UK’s nitazene problem. While this part reviews the nature, extent, and patterns of nitazene overdoses in the UK, the second will review policy options and make recommendations.

Introduction

Since June 2023, more than 750 deaths in the UK have been linked to nitazenes, a deadly synthetic opioid that is frequently more potent than fentanyl.

^[1] The National Crime Agency warned in 2024 that there has never been a more dangerous time to take drugs as nitazenes increasingly contaminated the UK drug supply.^[2]

The background of individuals who have fatally overdosed in nitazenes is diverse. Where some will owe to long-term exposure to hard substances, others will result from inadvertent consumption and naivety. In numerous cases, nitazene was present as a contaminant in what was believed to be a legal medicine to treat problems such as chronic pain or common mental health issues. As well as an adulterant to heroin, nitazene-laced substances are easily available online in the guise of legal medicine.

A sicker population is increasingly turning to dangerous forms of self-medication. With mental illness rising, the NHS failing, and lethal substances readily available and appearing safe, these cases may just be the beginning of a larger-scale crisis.

This overview of nitazenes in the UK spells out the seriousness of their threat and considers who is most at risk based on existing cases of overdoses. Whilst touching on all UK nations, it focuses on England as health policy is devolved. Dealing effectively with the UK’s opioid problem will require the effective marshalling of data to understand where resources are most needed. The analysis that follows is a warning of how far from that this country is.

This is not a moral panic about drug use. It is a warning about what happens when global criminal supply chains adapt faster than the British state, and when no one can say, with confidence, how many people have already died

1: Nitazenes in the UK

According to the Office for National Statistics (ONS), the number of English and Welsh nitazene-linked deaths almost quadrupled between 2023 and 2024 from 52 to 195 (Figure 1). 180 of these deaths occurred in England and 14 in Wales (one death is of a non-resident so was not attributed to either nation). In Scotland, nitazenes accounted for more than three times as many deaths in 2024 compared to 2023, according to the National Records of Scotland (NRS). No nitazene deaths have been recorded in Northern Ireland.

Figure 1: UK drug deaths linked to nitazenes and fentanyl, 2015-2024

Source: ONS, NRS^[3]

There may have been far more non-fatal overdoses. Freedom of Information (FOI) requests to ambulance services reveal that naloxone, which can treat opioid overdoses, was administered 16,254 times in England in 2024. The actual number of overdoses will be considerably higher because one ambulance service did not respond to FOI requests and naloxone is often administered by other individuals. In March 2025, Torbay Council in Devon introduced a new programme training members of the public to be ‘naloxone champions’ capable of administering the treatment.^[4] Some private employees, such as door supervisors at Professional Security, have also been trained to administer naloxone,^[5] whilst police in the UK administered the medication 1,232 times between June 2019 and December 2024.^[6] Not every naloxone use indicates a nitazene overdose, as it is also used to treat overdoses on other opioids. Nevertheless, these figures are indicative of a broader problem than suggested by the death statistics alone.

Numerous nitazene variants have been found in the UK. Table 1 shows common nitazene variants and their potency relative to heroin. The strongest in the table, etonitazene, is 10 times the strength of fentanyl which has ravaged the US. More nitazenes have been detected in the UK than are included in this table, with the government banning 14 specified variants between February 2023 and March 2024.^[7]

Both ONS data and a study of postmortems between 1 January and mid-October 2024 from the Imperial Toxicology Unit suggest that protonitazenes are the most commonplace.^[8] Whilst that is a weaker variant, it is still twice the potency of fentanyl.

Table 1: Strength of synthetic opioids relative to heroin Source: Social Market Foundation[9]
Fentanyl	50x
Metonitazene	50x
Protonitazene	100x
Isonitazene	250x
Etonitazene	500x

Nitazene consumers can experience euphoria, relaxation, concussion and sleepiness or, with higher doses, loss of consciousness. Because of their potency, there is a high risk of accidental overdose causing cardiorespiratory arrest and death. Both fentanyl and nitazenes are commonly found added to heroin and mixed with xylazine which can make the suppression of normal breathing much worse.^[10] They have also been found in cocaine, synthetic cannabis (‘spice’), and counterfeit medicines.^[11] Nitazenes often necessitate multiple doses due to their potency.^[12]

Nitazenes: the global context

The rising ubiquity of nitazenes has been driven by several international factors. In 2022, the Taliban introduced a ban on heroin, resulting in the global production of heroin falling 74% in 2023.^[13] The UK was particularly exposed to the subsequent surge in impure heroin because 95% of its heroin supply originates in Afghanistan, according to a 2023 government estimate.^[14]

However, the Taliban’s heroin ban does not in itself account for the presence of nitazenes in counterfeit pills such as diazepam, which is explored in the next section. Such drugs can easily be bought on the dark web, commonly originating in China and arriving in Royal Mail packages.^[15] As well as the dark web, nitazenes are sometimes advertised on TikTok, X, SoundCloud and even LinkedIn and have been provided by entities listed on China’s corporate register.^[16]

The surge in nitazenes coincides with China’s introduction of a fentanyl ban in 2019. As Figure 2 shows, between 2019 and 2023, the number of unique nitazenes reported to the UN Office on Drugs and Crime (UNODC) Early Warning Advisory (EWA) increased from 1 to 13. In the same period, the number of countries reporting fentanyl and analogues dropped dramatically.^[17] By 2024, more new nitazenes than new fentanyl analogues were being reported to UNODC.^[18] Just as drug markets adapted to the Taliban’s 2022 ban on heroin by providing more impure heroin, exporters responded to China’s clampdown on fentanyl by producing more nitazenes.

Figure 2: Number of unique fentanyl analogues and nitazenes reported to the UNODC EWA, 2012-23

Source: UNODC EWA^[19]

China’s latest introduction of a control on nitazene analogues in July 2025 may result in a drop of unique nitazenes available.^[20] However, there is also the risk that exporters respond by producing even more potent products, just as they responded to the new controls on fentanyl by turning to nitazenes.

The importation of nitazenes’ precursor chemicals for final synthesis in the UK is also a problem. In September 2025, Scottish police uncovered the first UK drug lab producing nitazenes operating in Ayrshire.^[21] Before this discovery, media reports on nitazenes had consistently identified China as the place of origin. This development, compared with previous reporting, is a reminder of how limited knowledge of these deadly narcotics remains.

UK drug deaths on the rise

The emergence of nitazenes follows a decade of rising drug deaths in the UK. According to the Commonwealth Fund, UK drug deaths are among the highest in the world as of 2022: Scotland had the third highest rate per million (behind the US and Puerto Rico); Wales had the fifth; Northern Ireland and England had the eighth and ninth, respectively.^[22] Between 2012 and 2024, deaths linked to drug misuse more than doubled in England and Wales both as a raw figure and population proportion.^[23]

The rate of drug-related deaths in Scotland remains the highest in Europe despite falling in 2024.^[24] Even at the reduced rate of 19.1 deaths per 100,000, the Scottish rate was more than three times as high as that of England and Wales which stood at 6.31 per 100,000. Northern Ireland’s rate stood at 9.1 per 100,000 in 2023, the last year for which figures are available, despite a decrease from the 2020 peak of 11.8 per 100,000.

Figure 3: Drug misuse deaths in the UK, 2005-2024

Source: ONS, NRS, NISRA^[25]

Note: rates are age-standardised

Nitazenes account for a relatively small number of total drug deaths. They have taken far fewer lives than heroin and morphine, which together account for the largest share at 1,415 deaths in England and Wales in 2024.^[26] However, the number of nitazene-related deaths is expanding at a much faster rate than both the overall number of drug deaths and the number of heroin and morphine-related deaths.^[27] If they continue on a similar trajectory, they could soon become a leading cause of drug-misuse deaths.

2. The limits of official statistics

Whilst these figures suggest a substantial rise in nitazene deaths, official underestimations of drug deaths mean that the real number of fatalities could be higher. The ONS released new data on drug deaths on 17 October, reporting 195 nitazene-linked deaths in 2024. However, nitazene deaths in England alone were probably much higher than that, with one alternative official estimate placing the figure at 303.

Neither the ONS nor Northern Ireland Statistics and Research Agency (NISRA) have access to post-mortem reports or toxicology results and instead rely on often incomplete information on death certificates provided by coroners. This problem appears to be getting worse, not better. The percentage of drug deaths in England and Wales for which no information is held on the specific substances involved increased from 13.9 in 2012 to 25.1 in 2021.^[28] A recent study from King’s College London suggests that ONS statistics may have underestimated opioid-related deaths by as much as 55%.^[29]

The deaths that make it into ONS statistics are also less up-to-date than they appear. Due to statistics on drug-poisoning deaths being based on the date of death registration, which may be delayed, 62.8% of deaths registered in 2024 occurred in previous years.

^[30] This time lag, in conjunction with drug deaths’ upward trajectory in England and Wales, means that ONS statistics may not have caught up with a higher death toll.

Indeed, the UK government set up an Early Warning System (EWS) whose data suggests that to be the case. The EWS covers England and is intended to track evolving threats from fentanyl, nitazenes and xylazine-like substances (the third is not an opioid but often found in the same laced substance). Whereas the ONS data released on 17 October states that 180 deaths in England were linked to nitazenes in 2024, the EWS states that 303 individuals did. For 2023, the EWS records 135 nitazene-linked deaths in England whilst the ONS records 52.^[31]

A Home Office press release from 24 October 2025 suggests that there have been significantly more nitazene-linked deaths in the UK than reported in any of these public data sources.^[32] The release states that nitazenes have been involved in more than 750 confirmed deaths between 1 June 2023 and 28 August 2025. That figure is not broken down, so it is not clear when these deaths occurred, but it either means that the latest ONS, NRS and NISRA statistics missed a significant number of deaths or that nitazene-linked deaths across the UK in 2025 stood at 270 by 28 August at least. However, this calculation (750 – total deaths reported by ONS, NRS and NISRA in 2023 and 2024) assumes that all the 2023 deaths occurred in the second half of the year, which is unlikely to be the case. The number of deaths linked to nitazenes between 1 January and 28 August 2025 is likely considerably higher than 270.

Table 2: Nitazene-linked deaths according to different UK authorities

Note: this table illustrates the divergence between official data sources rather than a reconciled total.

	Home Office 24 October 2025 press release	EWS (England)	National statistics authorities
			ONS (England and Wales)	NRS (Scotland)	NISRA (Northern Ireland)
2023	750 (from 1 June 2023)	135 (from 1 April)	52 (all in England)	23	0
2024		303	195 (180 in England, 15 in Wales)	76	x
2025 (to 28 August)		81 (to end September)	x	x	x
Total	750	519	346

However, the EWS states that nitazene deaths substantially declined in the year running to the end of September 2025 and that there were only 81 since January 2025.

It is entirely possible that this conclusion is incorrect. The EWS counts 519 nitazene-linked deaths between June 2023 and September 2025 while the Home Office press release counts 750 between June 2023 and August 2025. That leaves 231 of the deaths in the Home Office press release unaccounted for. We can subtract 14 that occurred in Wales, according to the ONS, 99 that occurred in Scotland in 2023 and 2024 according to the NRS (although that likely includes deaths that occurred in the first half of 2023), and the 38 nitazene deaths identified in Q1 2025 by Scotland’s Rapid Action Drug Alerts and Response (RADAR).^[33] Even under these conservative assumptions, that total is still 80 deaths short of the Home Office figure of 750.

These discrepancies suggest that official datasets are not capturing the full extent of nitazene involvement in drug-linked deaths. The EWS’s statement that the ‘number of recorded deaths linked to synthetic opioids has dropped significantly’ should therefore be seen with scepticism.^[34] Simply put, there is enormous inconsistency in official data. Official data sources cannot be reconciled, raising the possibility that policy decisions may be based on incorrect evidence whilst making it difficult to assess trends and the scale of the UK’s nitazene problem. This is a dangerous situation to be in when timely and accurate information will be vital for health authorities seeking to prepare for and respond to crises.

3: Who is most at risk? The drivers of nitazene overdoses

It is far from certain how many people might die as a result of nitazene poisoning, especially given the problems with official data. It is also difficult to estimate the likely number of nitazene-related deaths because so much is still unknown about them and the deaths that have occurred. This section therefore looks at who is plausibly at risk and draws attention to where more evidence is needed in order to better pre-empt future developments. A rough estimation of those at heightened risk of exposure to nitazenes is provided in table 3.

Table 3: number of people who may be at risk of exposure to nitazenes

Group	Size of group (estimate)
Heroin users	300,000
Individuals with anxiety	≥3.6 million
Individuals with ADHD	2.5 million
Individuals in moderately to severely debilitating chronic pain	8 million

Table 3 does not show the likely death toll of a UK opioid crisis. What it does show is that the potential market base for nitazene-laced drugs and the number of people who are conceivably exposed. It is not exhaustive. Certain groups that could plausibly have been included are not. For instance, individuals who use illicit vapes, in which nitazenes have been found, are excluded because it is not known how many people use these (although 4 million were seized at the UK border in 2024, suggesting a large number of people could be exposed to nitazenes through this route).^[35] Recreational drug users are also excluded because of sparse statistical information on this group. Although 2.9 million people reported using any drug in the crime Survey England and Wales at the last estimate, it is not known how many did so for recreational reasons.^[36]

Rather than attempting to scientifically or precisely calculate how many people may suffer a fatal overdose, this section looks at those who share a characteristic with those who have already died in the UK as a result of taking a nitazene.

Heroin users

Following the Taliban’s heroin ban, those with existing opioid abuse disorders are increasingly likely to consume heroin adulterated with synthetic substitutes. Whilst it is unknown how many people have opioid habits in the UK, a rough estimation can be made based on other figures. In the year from 1 April 2023 to 31 March 2024, 137,965 adults received treatment for problems with opioids. This number has remained around 140,000 for the last few years.^[37]

The latest official estimate of opiate use suggests that 293,863 used an opiate (129,584 also used crack cocaine and 164,279 an opiate alone) in 2019 to 2020.^[38] That means a little under half of those who used an opiate were in treatment at that time. Since treatment figures have only changed marginally, and so if the ratio between the two has maintained, we can assume that a similar number of people used an opiate in the last year and may be considered at risk of exposure to nitazenes.

Self-medication and mental illness 

Many of those in treatment for opioid addiction first took the substance years ago. But it is not only long-term users of hard drugs at risk. After two 2024 postmortem cases in London involving isonitazene revealed that the deceased individuals showed no signs of heroin or cocaine use, Imperial’s Toxicology Unit warned that ‘the user group has begun to broaden and is not just isolated to the typical heroin/cocaine users.’^[39]

Whilst nitazenes have been found in harder drugs such as heroin, they have also been found in much weaker drugs purchased on the dark net as seemingly innocuous pain killers including oxycodone, often sold as branded Percocet, as well as the sedative benzodiazapine (‘benzos’).^[40]

The frequency with which nitazenes have been found in benzos suggests that self-medication for mental illness is a significant driver of inadvertent nitazene consumption. Data from WEDINOS, the only national drug-checking service in the UK, shows that two thirds of samples containing nitazenes between 13 April 2024 and 13 April 2025 were supposed to be legal medicines and were bought legally; two thirds of this sub-category were supposed to be diazepam, a type of benzo.^[41]

There are several examples of young people turning to counterfeit medication to treat chronic pain and mental illness. 19-year-old Cerys Clark died in 2021 after taking what she believed to be Xanax, another benzo, and OxyContin to treat her scoliosis. In another instance, 23-year-old Alex Harprum died after consuming what he thought was Xanax to treat his ADHD. In both instances, the drug they had purchased online was laced with nitazenes.^[42] Another case, in Australia, involved an 18-year-old whose mother believed he bought fake oxycodone online to treat his anxiety.^[43] The link between illicit opioid and physical pain is well established (see below) and can be a driver of synthetic opioid use in its own right.

The turn to illicit medication is deeply worrying given the reported rise of young people suffering mental illness. According to NHS England, 852,742 children and young people accessed mental health services in the 12 months between November 2024 and October 2025, up from 693,561 in the same period in 2021-2.^[44] Whilst it is not clear how many of those suffer anxiety, the Children’s Commissioner has reported that in 2023-24 there were 204,526 new referrals of children where the primary cause was anxiety, up from 98,953 in 2019-20. 270,300 children and young people were still waiting for treatment at the end of the year after referral in 2022-23.^[45] In the adult population, about 7.5% or 3.4 million adults were estimated to suffer generalised anxiety disorder in June 2025 (the figure in table 3 adds this together with new children referrals, likely underestimating the real number).^[46]

2.5 million people were estimated to have ADHD in May 2025, 741,000 of whom were aged 5 to 24.^[47] Individuals seeking treatment for ADHD are also likely to be left waiting a considerable amount of time. In March 2025, up to 549,000 people may have been waiting for an ADHD assessment.^[48] The number of children referred for neurodevelopmental conditions including autism and ADHD has increased 30% and in March 2024 had the longest average waiting time of 223 days.^[49]

Self-medication and chronic pain

The link between chronic pain and illicit opioid consumption is well established. There is substantial evidence from the US and Canada that those involved in more physically demanding work or injured at work are at higher risk of opioid-related poisoning.^[50]

It is not known exactly how many UK adults are currently experiencing chronic pain and estimations vary greatly. UK Pain Messages states that about 8 million adults report moderate to severely disabling chronic pain,^[51] whereas the Health Foundation estimates that around 5 million patients in England experience chronic pain and project this figure to reach almost 7 million by 2040 due to demographic changes. By diagnosing chronic pain on the basis of having at least four prescriptions of analgesics or epilepsy drugs, the Health Foundation warns that these figures could underestimate the actual number. Public Health England stated in 2017 that 34% of people aged 16 or older suffered from chronic pain, rising to 53% for those over 75, which would be about 19 million.^[52] The number of individuals suffering from chronic pain in table 3 is, therefore, a lower estimate.

Chronic pain is often a starting point for addiction. There is a strong relationship between exposure to legally prescribed opioids and future likelihood of long-term use, with a greater initial supply increasing the likelihood.^[53] The US-fentanyl crisis is commonly thought to have been driven by the overprescription of pain medication in the 1990s, with a recent study suggesting that the drop in prescription opioid sales by more than a third between 2011 and 2019 helps explain the fall in fentanyl-linked deaths since 2023.^[54]

It is therefore justified that British commentators have expressed concern over prescription practices in the UK, with one observer highlighting that the UK had the highest consumption rate of prescription opioids in the world in 2019.^[55] Opioid prescriptions increased by 34% between 1998 and 2016.^[56] However, as the following section explores, the relationship between mental illness and chronic pain on the one hand and opioid overdoses on the other is a complex one.

Male and female overdose rates

Figure 4: Drug misuse death (age standardised) rate per million by sex in England and Wales, 2005-2024

Source: ONS^[57]

Men in England and Wales are roughly twice as likely as women to die from drug overdoses. The same pattern can be seen in the US where the age-adjusted rate of drug overdose deaths for males was 45.6 per 100,000 in 2022 compared to 19.4 per 100,000 for women.^[58]

EWS data suggests that the sex differential in overdose rates are even higher for nitazene-linked deaths. In the period covered by the EWS, 329 men died after nitazene consumption compared to 60 women, with 101 deaths of unknown sex. Presuming the sex distribution is similar in the unknown deaths, men are almost five and a half times more likely to die from nitazene consumption than women. Even if all the unknown deaths were female, men would still be twice as likely.

Figure 5: Number of nitazene-linked deaths by sex, January 2023 – September 2025

Source: EWS^[59]

This heightened sex disparity complicates the relationship between opioid deaths and legal prescriptions. A 2020 cohort study identified 1,958,742 new prescription opioid users between 2006 and 2017 in the UK, 57% of which were female.^[60] If opioid overdose deaths were driven by legal prescription alone, then men would not be as likely to die from synthetic opioids as they are since they constituted a smaller number of the population on prescribed legal opioids. However, this study did not consider the escalation of doses. Another study in Canada found that men are more likely to escalate to high-dose opioid therapy.^[61] Over-prescription could therefore substantially explain UK overdose deaths if they, like their Canadian counterparts, escalated to higher doses.

The greater probability of men escalating to higher doses of legal opioids is just one of the ways in which the sexes differ in their interaction with drugs. A US study suggests that because women were more likely to receive opioid prescriptions and more likely to be in contact with healthcare professionals prior to death, they encountered more opportunities for preventive treatment and harm reduction. It also points to men being more likely to consume fentanyl with alcohol.^[62] Another study found that men are less likely to engage in harm reduction practices, namely keeping naloxone to hand.^[63]

As well as engaging differently with drugs, broader differences between the sexes could help explain higher mortality in men. Men dominate physically demanding jobs like bricklaying, vehicle mechanics and machine operation which have been shown to increase the likelihood of opioid consumption.^[64] Whilst women more frequently suffer poor mental health, the sexes also experience mental illness differently. Male anxiety is more likely to relate to work-related stress while women’s mental wellbeing is more responsive to support from – or problems within – their social networks.^[65] That could help explain why men in the bottom quintile are so much more likely to die of a drug overdose than their female counterparts.

Figure 6: Drug mortality rates (age-standardised) by sex and deprivation quintile, 2024

Source: ONS^[66]

Young men and women also use their social networks in different ways. Whilst men draw on them to forget their troubles, often by going out and partying, women tend to use their networks to talk through their problems and generate solutions addressing their root causes.^[67] The sexes’ different levels of exposure and response to the personal drivers of opioid consumption have deep social roots.

Regional dynamics

Figure 7: Overdose rate per million by region, 2024

Source: ONS^[68]

Whilst the numbers of drug deaths vary significantly by region, overall drug death rates are not a reliable indicator of which regions are most at risk of nitazene exposure. ONS data shows that drug overdose rates have typically been highest in the North East and North West, with Yorkshire and the Humber overtaking the latter in 2023 and 2024 (see Figure 7). These are not the regions that have reported the highest numbers of nitazene-linked deaths. Based on 2024 ONS estimates of regional population size, London’s nitazene overdose rate was 17.27 per million over the period covered by the EWS, by far the highest, followed by the East of England and the East Midlands, both at 9.88. The North East and North West had the lowest at 3.26 and 2.58 respectively.

London stands out as the region worst affected by nitazenes to date. Freedom of Information requests to ambulance services reveal that London Ambulance Service administered naloxone on more occasions than most other services in the country. This data also reveals which boroughs seem to be worst affected, with ambulance services in Camden, Westminster and Lambeth treating the most opioid overdoses with naloxone in the period covered.

Figure 8: Nitazene-linked deaths by region, Q3 2023 – Q2 2025

Source: EWS,^[69] ONS^[70]

Note: deaths are aggregated from EWS reports (as of 24 December 2025) for England and overdose rates are calculated using ONS population statistics for mid-2024.

Figure 9: Naloxone incidents by London borough, 1 January 2023 – 31 September 2025

Source: FOI request

Naloxone administrations do not necessarily indicate where nitazenes are most prevalent. Notably, North East Ambulance Service recorded the highest number of naloxone incidents of services which responded, but had the second lowest rate of nitazene deaths and lowest raw number. The use of naloxone to treat overdoses on other opioids explains this disparity. The nitazene threat, then, is not necessarily highest where naloxone is most frequently administered, but the high number of naloxone incidents coupled with the rate of nitazene overdose deaths suggest London’s drug scene especially is becoming more dangerous.

Table 4: Naloxone administration by ambulance services in England, 2024

Source: FOI responses from UK ambulance services 

Ambulance service*	Patients receiving naloxone	Instances of naloxone being administered more than once (if provided)	Deaths after naloxone administered (if provided)
London Ambulance Services**	2,725	1,458
East Midlands Ambulance Service	1,784	945	70
East of England Ambulance Service	1,636	952
South East Coast Ambulance Service**	1,169	543	53
South Central Ambulance Service**	1,089	443	30
Yorkshire Ambulance Service	1,648	907
West Midlands Ambulance Service	2,347
North East Ambulance Service	3,069	799	58
North West Ambulance Service**	2,423	1,156	47

*South Western Ambulance Service did not respond to the FOI request so has been excluded.

**These ambulance services provided the number of incidents where naloxone was administered while the rest listed patients.

The asymmetry between general regional overdose rates and the rate of nitazene-linked deaths suggests that the latter are not a result of the social and geographical factors that drive higher overdose deaths in the less affluent parts of England. Rather, this pattern is likely accounted for by the contamination of particular local supplies, placing a greater premium on the gathering of timely and accurate information.

Conclusion: toward a better drug-death surveillance system

Nitazene deaths in the UK have climbed at a dramatic pace since 2022 and are probably even higher than official estimates. But inconsistencies and gaps in official data will hamstring health authorities’ ability to respond to the threat.

The particular patterns of nitazene deaths differ in certain ways from wider drug-linked death patterns, both in terms of the heightened sex disparity and a peculiar regional effect. In order to effectively address this growing crisis, health authorities will need to effectively gather and analyse data to understand such patterns and direct scarce resources where they are most needed. The problems with official data highlighted in this analysis suggest we are a long way from such capabilities.

The EWS is particularly problematic in giving the illusion of real-time data. Operating at a time lag of almost three months, there is nothing ‘early’ about it. Its conclusion that nitazene deaths are falling is open to question and if taken at face value risks providing false comfort. The government should address and clarify inconsistencies in official data as a matter of urgency.

The government (including both the previous Conservative and current Labour governments) has indicated that it is developing the EWS as a tool for helping local responders tackle the nitazene risk in their area.^[71] Yet the System relies on voluntary data sharing arrangements which vary from area to area, including coroners sharing toxicology results with local authorities and onward sharing with national authorities.

Because the October 2025 Home Office press release gives the highest estimate of nitazene-linked deaths, it seems to be the most thorough. Whatever surveillance methods underlie the figure it provides should become the norm for data collection. Because of its thoroughness, there is the possibility that its method is too onerous to provide timely data. However, given that it provided data on deaths up to two months prior to its release, the underlying method can probably be carried out faster than that used by the EWS.

If the method underlying the Home Office press release is not scalable, Canada offers a model the UK would do well to emulate. Canada has established a national system – the Canadian Coroner and Medical Examiner Database (CCMED) – that aggregates detailed death investigation data into a single source.^[72] The ONS, by contrast, relies on death registrations rather than coroners reports which are not routinely shared with central authorities.^[73] Moving toward a system like the CCMED would be a positive step toward building a clearer picture of the real scale of the UK’s opioid problem.

There is also the possibility of gaining greater granularity through harmonising multiple data sources. British Columbia’s various health authorities collaborated to construct an Overdose Cohort for 2015 and 2016 which drew on distinct data sets including ambulance reports, emergency calls, patient historic health data and more. This Cohort yielded insights into relevant risk and protective factors including sex and age-based dynamics. It also captured behavioural insights, showing that fatal overdose events mainly occurred without connection to health services, reinforcing the contention that those who die are consuming potent drugs alone. Such insights can be used to refer those at risk to appropriate services in a timely manner.^[74] However, such data collection is onerous and time consuming, requiring complex steps to link the disparate sources. Evidently, there is a tradeoff between detail and timeliness.

The problem of timeliness is hard to circumvent. Even the most efficient systems will operate on a time delay. British Columbia maintains an Unregulated Drug Poisoning Emergency Dashboard with multiple data inputs – including paramedic attended events, unregulated drug deaths, naloxone distribution and more – which is updated bimonthly. However, the Dashboard still operates on a timelag of several weeks.^[75] In order to respond to an imminent crisis in which a local supply has been contaminated, well-developed Local Drug Information Systems (LDISs), combining relevant local authorities with service providers who are trusted by drug users, are required. Cultivating such networks raises a number of complex policy and philosophical questions relating to law enforcement and harm prevention which will be addressed in part 2 of this report.

Acknowledgements: I would like to thank Ellie Craven, Caroline Elsom and Yamini Cinamon Nair for commenting on drafts of this report and Neil Mendoza for encouraging me to research synthetic opioids. Any errors are my own.

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[1] “UK unleashes first dogs trained to detect synthetic opioids” – Home Office news story, 24 October 2025 (link).

[2] “There has never been a more dangerous time to take drugs, says NCA as annual threat assessment is published” – NCA, 15 August 2024 (link).

[3] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link); Drug-related deaths in Scotland, 2024, NRS, 2 September 2025 (link). Note: The ONS, NRS and NISRA do not use consistent categories in reference to fentanyl and the original terminology has been retained. NISRA data is only available up to 2023 and does not include nitazenes.

[4] “Members of the public urged to help prevent drug overdoses” – Torbay Council, March 2025 (link).

[5] ‘‘All door staff should carry life-saving drug” – BBC News, 22 September 2025 (link).

[6] Lord Mendoza: Written questions, 17 September 2025 (link).

[7] “Synthetic opioids to be banned as government acts to stop drug deaths – Home Office news story, 3 February 2023 (link); “More synthetic opioids banned to protect communities” – Home Office news story, 20 March 2024 (link).

[8] Nahar, Limon K., Andrews, Rebecca and Paterson, Sue, “Opioid crisis: Fall in US overdose deaths leaves experts scrambling for an explanation” – BMJ, 286, 31 October 2024 (link).

[9] Shepherd, Jake, “Turning the tide on nitazenes and other dangerous drugs” – Social Market Foundation, 11 December 2024 (link).

[10] Synthetic opioids – Frank (link).

[11] Royal Greenwich Combating Drugs Partnership (CDP) (link).

[12] Amaducci, Alexandra et al, “Naloxone Use in Novel Potent Opioid and Fentanyl Overdoses in Emergency Department Patients” – JAMA Network Open, 29 August 2023 (link).

[13] Duddy, Claire and Downs, Williams, “Misuse of drugs: regulation and enforcement” – House of Commons Library, 4 December 2024, p. 2 (link).

[14] No place to hide: serious and organised crime strategy 2023 to 2028 – Home Office, 17 April 2024 (link).

[15] Martin, Amy-Clare, “Revealed: Deadly epidemic of super-strength Chinese opioids gripping Britain’s streets” – Independent, 17 May 2024(link).

[16] McLennan, William, Campbell, Colin and Newbery, Abby, “Deadly opioids smuggled into UK in dog food, BBC learns” – BBC News, 22 April 2024 (link); “The Rise of Nitazenes: Chinese Suppliers Behind Ads for Deadly Opioids Targeting Europe” – Bellingcat, 20 January 2025 (link); “Fentanyl: Germany prepares for synthetic drugs crisis” – DW, 15 September 2025 (link).

[17] “February 2024 – UNODC EWA: Nitazenes – a new group of synthetic opioids emerges” – UNODC (link).

[18] World Drug Report 2025: Key Findings, UNODC, June 2025, pp. 20, 23 (link).

[19] “February 2024 – UNODC EWA: Nitazenes – a new group of synthetic opioids emerges” – UNODC (link).

[20] “July 2025 – China: Announcement of class scheduling of ‘nitazenes’ analogues”, UNODC, 1 July 2025 (link).

[21] “Drug lab developing synthetic opioids found in Ayrshire” – BBC News, 25 September 2025 (link).

[22] Gumas, Evan D., “U.S. Overdose Deaths Remain Higher Than in Other Countries — Trend-Tracking and Harm-Reduction Policies Could Help” – The Commonwealth Fund, 9 January 2025 (link).

[23] Drug misuse deaths are a subset of drug poisoning, the number of which is far higher. The ONS defines drug misuse deaths as those in which meet one or both of the following criteria: ‘the underlying cause is drug abuse or drug dependence’; ‘any of the substances involved are controlled under the Misuse of Drugs Act 1971’. Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link).

[24] “Scottish drug deaths fall but remain worst in Europe” – BBC News, 1 September 2025 (link).

[25] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link); Drug-related deaths in Scotland, 2024, NRS, 2 September 2025 (link); Drug-Related Deaths, NISRA (link). Note: The ONS, NRS and NISRA do not use consistent categories in reference to fentanyl and the original terminology has been retained. NISRA data is only available up to 2023 and does not include nitazenes.

[26] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link)

[27] ONS data shows that the number of drug misuse-linked deaths involving heroin/morphine has held relatively steady at between 1,164 and 1,453 between 2015 and 2024. The mean since 2015 is 1,291.3 deaths per year; the peak of 1,453 was 12.5% higher than the mean whilst the lowest number of 1,164 was 9.9% lower.

[28] Breen, Paul, “Comparability of drug-related death statistics across the United Kingdom” – Analysis Function, 4 August 2023 (link).

[29] Copeland, Caroline, “Opioid-related deaths in past decade 55% higher than recorded” – King’s College London, 16 September 2025 (link).

[30] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link).

[31] Drugs early warning system dashboard, Department of Health & Social Care (link).

[32] “UK unleashes first dogs trained to detect synthetic opioids” – Home Office news story, 24 October 2025 (link).

[33] Rapid Action Drug Alerts and Response (RADAR), Public Health Scotland, July 2025 (link).

[34] Drugs early warning system dashboard, Department of Health & Social Care (link).

[35] Lawley, Sam, “My son died after a smoking vape ‘laced with opioid 20 times more powerful than fentanyl’ but no one has ever heard of… I don’t want other families to go through our pain” – Daily Mail,12 August 2025 (link);  “Over four million illegal vapes seized at border” – BBC News, 27 January 2024 (link).

[36] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link).

[37] Adult substance misuse treatment statistics 2023 to 2024: report – Office for Health Improvement & Disparities, 28 November 2024 (link).

[38] Estimates of opiate and crack use in England 2016 to 2020: main points and methods – Department of Health & Social Care / UK Health Security Agency, 28 October 2025 (link).

[39] Nahar, Limon K., Andrews, Rebecca and Paterson, Sue, “Opioid crisis: Fall in US overdose deaths leaves experts scrambling for an explanation” – BMJ, 286, 31 October 2024 (link).

[40] ACMD advice on 2-benzyl benzimidazole and piperidine benzimidazolone opioids – Advisory Council on the Misuse of Drugs, 10 December 2025 (link); “Are you getting what you think you’re getting?” – WEDINOS, 11 December 2023 (link).

[41] “My son died after a smoking vape ‘laced with opioid 20 times more powerful than fentanyl’ but no one has ever heard of… I don’t want other families to go through our pain” – Daily Mail,12 August 2025 (link).

[42] “How drug TWO THOUSAND times the strength of heroin is killing Brits… as expert warns deaths are ‘tip of the iceberg’ and UK could ‘face US-style fentanyl epidemic” – Daily Mail, 13 April 2025 (link).

[43] Gwynn, Liz, “Parents plea for awareness after fake oxycodone laced with nitazene causes son’s death” – ABC, 17 August 2024 (link).

[44] Mental Health Services Monthly Statistics Dashboard, NHS England (link).

[45] “Children’s Commissioner responds to new figures on children referred to mental health support for anxiety” – Children’s Commissioner, 6 September 2024 (link).

[46] Adult Psychiatric Morbidity Survey: Survey of Mental Health and Wellbeing, England, 2023/4 – NHS England, 27 November 2025 (link).

[47] ADHD Management Information – May 2025, NHS England, 29 May (link).

[48] ADHD Management Information – May 2025, NHS England, 29 May (link).

[49] “Press Notice: Children’s Commissioner calls for urgent action to tackle waiting times and inequality in mental health care for children” – Children’s Commissioner, 18 May 2025 (link).

[50] Carnide Nancy, et al, “Risk of opioid-related harms by occupation within a large cohort of formerly injured workers in Ontario, Canada: findings from the Occupational Disease Surveillance System” – Occupational and Environmental Medicine, 81, 2024(link).

[51] UK Pain Messages 2024 (link).  

[52] Watt, Toby et al, Health in 2040: projected patterns of illness in England – REAL Centre, July 2023, p. 39 (link).

[53] Hadlandsmyth, Katherine, Lund, Brian C. and Mosher, Hilary J., “Associations between initial opioid exposure and the likelihood for long-term use” – Journal of the American Pharmacists Association, 59(1), 2019 (link).

[54] “Fentanyl and the U.S. Opioid Epidemic” – Council on Foreign Relations, 30 October 2025 (link); Dowell, Deborah et al, “Why have overdose deaths decreased? Widespread fentanyl saturation and decreased drug use among key drivers”, The Lancet Regional Health – Americas, 51, 2025(link).

[55] Weisberg, Daniel F., “Prescription opioid misuse in the United States and the United Kingdom: Cautionary lessons” – International Journal of Drug Policy, 25(6), 2014  (link); Gill, Martha, “Britain is not yet an opioid nation but rising drug deaths demand a new approach” – The Observer, 21 September 2025 (link). The research establishing this data: Jayawardana, Sahan et al, “Global consumption of prescription opioid analgesics between 2009-2019: a country-level observational study” – eClinicalMedicine, 42, December 2021 (link).

[56] Curtis, Helen J. et al, “Opioid prescribing trends and geographical variation in England, 1998–2018: a retrospective database study” – The Lancet, 6(2), February 2019 (link).

[57] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link).

[58] Spencer, Merianne R., et al, Drug Overdose Deaths in the United States, 2002-2022 – NCHS Data Brief No. 491, March 2024 (link). Research into synthetic opioids specifically has found that men are more likely to overdose on these substances in the US. See Butelman, Eduardo R., “Overdose mortality rates for opioids and stimulant drugs are substantially higher in men than in women: state-level analysis” – Neuropsychopharmacology, 48, 2023 (link).

[59] Drugs early warning system dashboard, Department of Health & Social Care (link).

[60] Jani, Meghna, “Time trends and prescribing patterns of opioid drugs in UK primary care patients with non-cancer pain: A retrospective cohort study” – PLoS Med, 17(10), October 2020 (link).

[61] Kaplovitch, Eric et al, “Sex Differences in Dose Escalation and Overdose Death during Chronic Opioid Therapy: A Population-Based Cohort Study” – PLoS Med, 10(8), August 2015 (link).

[62] Wightman, Rachel S. et al, “Toxicological and pharmacologic sex differences in unintentional or undetermined opioid overdose death” – Drug and Alcohol Dependence, 227, 1 October 2021 (link)

[63] Shaw, Leah C. et al, “Gender-based differences in harm reduction practices among people who use drugs in Rhode Island: a latent class analysis” – Harm Reduction Journal, 22(140), 18 August 2025 (link).

[64] The occupations most dependent on older and younger workers, ONS, 31 May 2023 (link); Francis-Devine, Brigid, “The gender pay gap” – House of Commons Library, 17 November 2025, p. 21 (link).

[65] Weiß, Martin, “Differential network interactions between psychosocial factors, mental health, and health-related quality of life in women and men” – Scientific Reports, 13, 18 July 2023 (link).

[66] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link).

[67] Martínez-Hernáez, Angel et al, “Social support and gender differences in coping with depression among emerging adults: a mixed-methods study” – Child and Adolescent Psychiatry and Mental Health, 10(2), 7 January 2016 (link).

[68] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link).

[69] Drugs early warning system dashboard, Department of Health & Social Care (link).

[70] Deaths related to drug poisoning in England and Wales: 2024 registrations, ONS, 17 October 2025 (link).

[71] Local preparedness for synthetic opioids in England – Home Office, 23 June 2025  (link).

[72] Canadian Coroner and Medical Examiner Database, January 2006 to May 2025, Statistics Canada, 4 June 2025 (link).

[73] Coroner areas in England and Wales, ONS, 20 June 2025 (link).

[74] MacDougall, Laura et al, “Development and characteristics of the Provincial Overdose Cohort in British Columbia, Canada” – PLoS One, 14(1), 10 January 2019 (link). Also see: BC Provincial Overdose Cohort, BC Centre for Disease Control (BCCDC) (link).

[75] BCCDC, Unregulated Drug Poisoning Emergency Dashboard, Tableau Public (link).