Intended for healthcare professionals

Letters Second generation mephedrone

The confusing case of NRG-1

BMJ 2010; 341 doi: (Published 06 July 2010) Cite this as: BMJ 2010;341:c3564
  1. Simon D Brandt, senior lecturer in analytical chemistry1,
  2. Harry R Sumnall, reader in substance use2,
  3. Fiona Measham, senior lecturer in criminology3,
  4. Jon Cole, reader in psychology4
  1. 1School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool L3 3AF
  2. 2Centre for Public Health, Liverpool John Moores University, Liverpool L3 2AJ
  3. 3Department of Applied Social Science, Lancaster University, Lancaster LA1 4YT
  4. 4School of Psychology, University of Liverpool, Liverpool L69 7ZA
  1. s.brandt{at}

    Since the recent ban on mephedrone,1 2several alternative products have been introduced on internet websites. One of the most prominently discussed second generation products is Energy 1 (NRG-1), also advertised as naphyrone (naphthylpyrovalerone, O-2482), which originated from a group of compounds previously described in the medicinal chemistry literature.3

    These products are offered as legal substitutes for the recently criminalised “legal highs,” the mephedrone derivatives. One of the earlier studies exploring the motivation for using these drugs suggested that consumers think that they are more likely to be of higher purity than street drugs, carry a lower risk of physical harm, and not be liable for the criminal sanctions associated with drugs controlled under the Misuse of Drugs Act.4

    To obtain an initial snapshot of the post-ban situation, we purchased 17 products online from 12 UK based websites over the six weeks after the ban on mephedrone in mid-April 2010. Chemical analysis was carried out by established procedures (table 1).5

    NRG-1 and NRG-2 products purchased online from UK based websites in the 6 weeks after the ban on mephedrone

    View this table:

    Most of the NRG-type products were recently banned cathinones that just carried a new label; this suggests that both consumers and online sellers are, most likely without knowledge, at risk of criminalisation and potential harm. This has important health and criminal justice consequences that will require carefully thought out responses and further investigation.


    Cite this as: BMJ 2010;341:c3564


    • Competing interests: None declared.


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