New psychoactive substances (NPS), plant and mushroom toxins

New psychoactive substances (NPS) are synthetic, semi-synthetic or natural compounds, sometimes sold as “legal” alternatives to illicit drugs. NPS substances are continuously modified to avoid existing legislation. In addition, drugs no longer in use in a regulated environment or drugs which never reached the market are also resurfacing on the drug scene. The European monitoring center for drugs and drug addiction (EMCDDA) monitors around 950 NPS substances.

NPS are continuously being introduced to illegal drug markets worldwide. One of the research group’s focus areas is to update our analytical repertoire and develop new methods for NPS, to keep up with the changing trends.

Another focus area is to develop a new screening method for plant and mushroom toxins in blood. The aim is to improve diagnostics and knowledge about such poisonings.

In collaboration with members of other research groups at our department or at the University of Oslo, we develop new sensitive methods, including development and use of novel techniques for sample preparation or instrumentation, as well as studies of NPS metabolism using human microsomes or hepatocytes.

Photo: Seized solutions containing 4-fluoromethamphetamine and 4-fluoroamphetamine. ©Division of Forensic Sciences, Oslo University Hospital.

Ongoing projects

Synthetic opioids, tryptamines and ketamines.

Several projects are ongoing or have been undertaken concerning the development of sensitive methods for analysis of new designer drugs such as nitazenes (synthetic opioids), tryptamines and ketamine analogues and metabolism studies in vitro using preparations of human liver cells (microsomes). A project for developing micro-extraction techniques for analysis of ketamine analogues are currently conducted in collaboration with researchers from the Department of Pharmacy at the University of Oslo.

If you have questions about the project or suggestions for research collaboration, please contact: Åse Marit Leere Øiestad ( or Elisabeth Leere Øiestad (

Nitazen-related deaths in Norway

In this project, we present nitazene blood concentrations in nitazen-related deaths in Norway from their appearance in 2021, to gain more knowledge about this class of abused drugs. Nitazenes are strong synthetic opioids (pain killers) that were never approved to the medicinal drug market because of the high overdose risk. In 2019, nitazenes appeared on the illegal drug market in Europe. By 2023, 12 nitazenes have been registered, and often in relation to fatal intoxications.

If you have questions about the project or suggestions for research collaboration, please contact: Merete Vevelstad (

Plant and mushroom toxins

A new analysis method will be able to screen for a large selection of plant and mushroom toxins in biological samples, such as blood or urine. For this, advanced mass spectrometry techniques with UHPLC-QTOF-MS (liquid chromatography quadrupole time-of-flight /mass spectrometry) are used. A reference library is under development, including the most relevant toxins, by analysis of collected plant and mushroom material and reference standards. We have also established a national interdisciplinary “Competence group for plant and mushroom toxins”, consisting of medical specialists in pharmacology and anesthesia, chemists, and veterinarians contributing to the project.

If you have questions about the project or suggestions for research collaboration, please contact: Merete Vevelstad (

News and Media Reports

Bedret diagnostikk av plante- og soppforgiftninger - Oslo universitetssykehus (

Nitazener – svært potente opioider - FMR: Fellesskap - Menneskeverd - Rusfrihet



  • Stig Pedersen-Bjergaard (Professor), Department of Pharmacy, University of Oslo, Norway
  • Maria Schüller (PhD candidate), Department of Pharmacy, University of Oslo, Norway
  • Steven Ray Wilson (Professor), Department of Chemistry, University of Oslo and Hybrid Technology-Hub, Centre of Excellence, Norway
  • Katharina Elisabeth Grafinger, Institute of Chemistry and Bioanalytics, University of Applied Sciences and Arts Northwestern Switzerland, Switzerland
  • Anita von Krogh (Senior advisor/ veterinarian), Norwegian Poison Information Centre, Norwegian Institute of Public Health, Norway
  • Henrik Andreas Torp (MD, PhD candidate), Department of Anesthesiology, Oslo university hospital and Norwegian Poison Information Centre Norway.
  • Arne Helland (Associate professor), Department of Clinical Pharmacology, St. Olav University Hospital
  • Per Ole Gundersen (Scientist, PhD), Department of Clinical Pharmacology, St. Olav University Hospital
  • Marilyn Huestis (Professor), Institute of Emerging Health Professions, Thomas Jefferson University, Philadelphia, USA


Schüller M, Lucic I, Øiestad ÅML, Pedersen-Bjergaard S, Øiestad EL (2023)
High-throughput quantification of emerging “nitazene” benzimidazole opioid analogs by microextraction and UHPLC–MS-MS
Journal of Analytical Toxicology, 47(9), 787–796
DOI 10.1093/jat/bkad071

Vevelstad MS, Øiestad ÅML, Johansen U, von Krogh A, Torp H A (2022)
Barlind – en giftig og myteomspunnet busk med medisinsk potensial.
Kronikk. Tidsskriftet for den norske legeforening, Volum 142.

Bergh MSS, Bogen IL, Nerem E, Wohlfarth A, Wilson SR, Øiestad ÅML (2021)
Discovering the major metabolites of the three novel fentanyl analogues 3-methylcrotonylfentanyl, furanylbenzylfentanyl, and 4-fluorocyclopropylbenzylfentanyl for forensic case work
Forensic Toxicol., 39 (1), 167-178
DOI 1007/s11419-020-00560-9

Bergh MS, Øiestad ÅML, Baumann MH, Bogen IL(2020)
Selectivity and sensitivity of urine fentanyl test strips to detect fentanyl analogues in illicit drugs
Int J Drug Policy, 90, 103065
DOI 1016/j.drugpo.2020.103065, PubMed 33333419

Heide G, Høiseth G, Middelkoop G, Øiestad ÅML(2020)
Blood Concentrations of Designer Benzodiazepines: Relation to Impairment and Findings in Forensic Cases
J Anal Toxicol, 44 (8), 905-914
DOI 1093/jat/bkaa043, PubMed 32369173

Bergh MS, Bogen IL, Wohlfarth A, Wilson SR, Øiestad ÅML(2019)
Distinguishing Between Cyclopropylfentanyl and Crotonylfentanyl by Methods Commonly Available in the Forensic Laboratory
Ther Drug Monit, 41 (4), 519-527
DOI 1097/FTD.0000000000000617, PubMed 30807539

Bergh MS, Bogen IL, Wilson SR, Øiestad ÅML(2018)
Addressing the Fentanyl Analogue Epidemic by Multiplex UHPLC-MS/MS Analysis of Whole Blood
Ther Drug Monit, 40 (6), 738-748
DOI 1097/FTD.0000000000000564, PubMed 30157097

Vårdal L, Wong G, Øiestad ÅML, Pedersen-Bjergaard S, Gjelstad A, Øiestad EL(2018)
Rapid determination of designer benzodiazepines, benzodiazepines, and Z-hypnotics in whole blood using parallel artificial liquid membrane extraction and UHPLC-MS/MS
Anal Bioanal Chem, 410 (20), 4967-4978
DOI 1007/s00216-018-1147-y, PubMed 29947895

Mardal M, Johansen SS, Davidsen AB, Telving R, Jornil JR, Dalsgaard PW, Hasselstrøm JB, Øiestad ÅM, Linnet K, Andreasen MF(2018)
Postmortem analysis of three methoxyacetylfentanyl-related deaths in Denmark and in vitro metabolite profiling in pooled human hepatocytes
Forensic Sci Int, 290, 310-317
DOI 1016/j.forsciint.2018.07.020, PubMed 30107329

Øiestad ÅML, Berg T, Eliassen E, Wiklund T, Sand K, Øiestad EL(2018)
Separation of isomers of new psychoactive substances and isotope-labeled amphetamines using UHPSFC-MS/MS and UHPLC-MS/MS
Liq. Chromatogr. Relat. Technol., 41 (7), 391-400
DOI 10.1080/10826076.2017.1388818

Øiestad EL, Ritva K, Haugland K, Øiestad ÅM. (2017)
Screening of synthetic cannabinoids, in The Handbook of Cannabis and Related Pathologies: Biology, Pharmacology, Diagnosis, and Treatment
V.R. Preedy, Editor. Academic Press, pp. 981

Vallersnes OM, Persett PS, Øiestad EL, Karinen R, Heyerdahl F, Hovda KE(2017)
Underestimated impact of novel psychoactive substances: laboratory confirmation of recreational drug toxicity in Oslo, Norway
Clin Toxicol (Phila), 55 (7), 636-644
DOI 1080/15563650.2017.1312002, PubMed 28406320

Vårdal L, Askildsen HM, Gjelstad A, Øiestad EL, Edvardsen HM, Pedersen-Bjergaard S(2017)
Parallel artificial liquid membrane extraction of new psychoactive substances in plasma and whole blood
J Chromatogr B Analyt Technol Biomed Life Sci, 1048, 77-84
DOI 1016/j.jchromb.2017.02.010, PubMed 28226266

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