Safer Tripping: Serotonergic Psychedelics and Drug Checking. Submission and Detection Rates, Potential Harms, and Challenges for Drug Analysis

This multinational harm-reduction study (2021) investigated the presence and proportion of serotonergic psychedelics submitted to drug checking services across the Netherlands, Spain, UK, Italy, Portugal, Belgium, Canada, and Australia. They detected a considerable amount of novel synthetic phenethylamine psychedelics, such as NBOMes with higher levels of toxicity and unpredictably prolonged effect duration, within samples sold as LSD or MDMA.


Purpose of Review: With the continuous emergence of new psychoactive substances, drug checking (DC) services are challenged by an increasingly complex drug market. Considering the resumed scientific and public interest in serotonergic psychedelics (SPs) like LSD, psilocybin, and 2C-B, we present the results of a literature search investigating the presence and proportion of SPs in DC samples.

Recent Findings: In 15 identified reports, submission and detection rates of SPs were comparably low, but increasing. Samples contained considerable amounts of adulterations or analogues, mostly novel SPs with unknown toxicological profiles and in some cases potentially life-threatening effects. The detection of SPs, however, requires advanced analysis techniques currently not available to most DC services.

Summary: Given the substantial proportion of novel SPs in DC samples and the associated risks, DC can be a valuable harm reduction and monitoring tool for SPs if analysis techniques with high sensitivity are employed.”

Authors: Tim Hirschfeld, Laura Smit-Rigter, Daan van der Gouwe, Simon Reiche, Heino Stöver & Tomislav Majić


We present the results of a literature search investigating the presence and proportion of serotonergic psychedelics in drug checking samples.


Drug checking (DC) is a harm reduction tool that enables potential substance users to anonymously submit samples of substances they intend to use for chemical analysis. DC provides fact-based information on the composition of substances and a consultative talk provided by a trained staff.

Originally, DC services detected stimulants like MDMA, amphetamine, and cocaine. However, the illicit substance market has become more complex, and DC services are now required to detect and monitor evermore substances.

SPs like LSD, psilocybin, DMT, and mescaline act at type 2A serotonin (5-HT2a) receptors and are used to induce psychedelic effects. New synthetic SPs are not controlled by the 1961 Single Convention on Narcotic Drugs or the 1971 Convention on Psychotropic Substances.

SPs can be categorised into three main chemical types of 5-HT2a agonists: tryptamines, lysergamides, and psychedelic phenethylamines. The variety of novel SPs is particularly pronounced in the phenethylamine group due to the comparably easy synthesisation and the large amount of possible modifications.

Besides their addictive potential, stimulants, opioids, and other substances are predominantly associated with physical risks. However, novel substances like NBOMes may become an increasing public health concern.

Given the recently increased interest in SPs use, the continuous emergence of novel SPs, and the potential psychological harms associated with recreational SPs use, the present review investigated the relevance of SPs in currently operating DC services.


To investigate the presence of synthetic substances in recent drug testing, a literature search was performed in PubMed, Google Scholar, and hand-searched references were screened.

Results on Serotonergic Psychedelics in Submitted Drug Checking Samples

A search strategy in PubMed yielded 184 records, of which 14 contained original information on submission or DC of SPs by drug checking services.

The Netherlands

The prevalence of NPS in forensic samples and poison centre data increased over the last decade, despite considerable annual variations. NPS incidence rates significantly increased in DC samples between 2013 and 2016.

Between 2013 and 2017 DIMS detected 11 different tryptamines and 19 different psychedelic phenethylamines, including DOx, AMT, and NBOMes. LSD was the most prevalent SP, followed by 2C-B, and 2C-T-2 and 2C-T-7 were increasingly found in LSD and ecstasy samples.


The DC service “Energy Control” reported a progressive increase in samples submitted as tryptamines between 2006 and 2015, and found that 4.8% of regulated tryptamines contained no active substance, compared to 2.2% of unregulated tryptamines. The most frequently detected NPS adulterant was 2C-B, which was found especially often in MDMA tablets.

Measham evaluated a stationary DC service in 2 cities in 2018 and identified SPs in 14.6% of all submitted samples. SPs included LSD, 2C-B, DMT, mescaline, and 5-MeO-MiPTin additionto25C-NBOHand25D-NBOMe mis-sold as LSD.


In 2018, multiple NPS were found at multiple music festivals, including 2C-x (n = 7) and 31 unknown substances.


The on-site DC service at the 2016 electronic open-air festival “Boom” detected 11.6% of expected LSD samples as being adulterated, and 67.3% of LSD samples contained only LSD, 0.8% contained adulterations, and 7.8% contained no psychoactive substance.


Similar adulterations were found at 27 music events across Italy during 2016 and 2017; in 2019, no adulterations or analogues were found in the 4 SPs samples submitted at 5 music events in Italy.


In the present review, we found that SPs constitute a relatively low but increasing proportion of all submitted substances to DC services, and that unexpected SPs were common in mis-sold (non-psychedelic) samples.

The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) and the United Nations Office on Drugs and Crime (UNODC) report that in 2018 LSD accounted for 9.4% of all submitted samples and NPS in general for 3.9%. Novel SPs were the second most common NPS class detected after stimulants.

Harms Associated with Serotonergic Psychedelics

Psychological effects of psychedelic substances depend on the drug, the set, and the environment in which they are used. Recreational use of psychedelic substances may be associated with an increased risk of adverse reactions or subacute and long-term persisting adverse psychological effects.

Novel serotonin releasing agents (SRs) have unknown acute toxicity and long-term health effects. They belong to the phenethylamine groups DOx, 2C-x, and NBOMes and exhibit full agonist action at 5-HT2a sites. A systematic review identified 70 cases of intoxication by NBOMes, of which 7 (10%) were fatal. The risk of overdosing is especially great when NBOMes are nasally insufflated, but also increases with sublingual or buccal administration of blotter papers. Animal studies indicate neuro- and genotoxic properties of certain SPs, such as 5-MeO-DIPT, 2C-C, 2C-P, and 25B-NBOMe. In the case of 2C-B, severe neurological reactions have also been reported.

SPs can cause profound psychological effects, which can lead to accidents and other harmful and potentially fatal behaviours. Long-acting phenethylamine psychedelics like DOB and DOI can cause acute adverse psychological effects, which could be especially problematic by using mis-sold non-psychedelic samples. There are several reports of psychological effects associated with SPs, including psychosis, hallucinogen persisting perception disorder, and depersonalisation/derealisation syndrome.

Taken together, the purity, dosage and appropriate set and setting of SPs can reduce physical and psychological harms to the user. DC is a valuable tool for reducing risks.

Challenges for Drug Checking in Reducing Psychedelic-Related Harm

First and foremost, the extent of harm reduction relies on the accuracy and reliability of the analysis results. This requires the use of high-sensitivity analysis techniques and reference standards.

The substantial number of novel substances in drinks may not be detected by traditional methods, so qualitative techniques such as Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, low-voltage paper spray ionisation quadrupole time-of-flight (QTOF)-MS, thin-layer chromatography, or colorimetric reagent tests may be used.

If organisations or safer nightlife projects are not allowed to analyse substances, RS could be used to prevent legal risks. However, given the limited sensitivity and specificity of qualitative analysis techniques, collaboration with laboratories should be considered.


The increasing interest in serotonergic psychedelics and the potential risks and harms associated with their use justify efforts to establish advanced analysis techniques. Despite the low submission rate of serotonergic psychedelics to drug detection services and the considerable cost of their analyses, drug detection services are valuable tools for raising awareness.

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