Fantasy islands - The emergence of NMP in GBL-containing liquids in New Zealand

•New Zealand has experienced a large increase in GBL seizures that also contain NMP.•The majority of the GBL and NMP mixtures had similar compositions.•Mixtures likely to have been diverted from a legitimate industrial chemical.•Users are unlikely to be aware of the presence of NMP in the GBL liquids.•Health effects for the recreational consumption of NMP are unknown. Over the last few years there has been a dramatic increase in the amount of “Fantasy” type drugs seized in New Zealand, with gamma-butyrolactone (GBL) being by far the most prevalent. In 2018, N-methyl-2-pyrrolidone (NMP) was detected in a liquid, along with GBL, for the first time in New Zealand. Since this seizure, the number of seizures containing mixtures of GBL and NMP that have been submitted for analysis by New Zealand authorities have significantly increased, with 82% of submitted samples containing GBL also containing NMP. Analysis of these liquids showed that the majority had GBL and NMP purities of approximately 60–70% and 30–40%, respectively. Subsequent investigations by New Zealand authorities revealed a potential source of these liquids being a diverted legitimate industrial product. The health and psychoactive effects of NMP, along with GBL and NMP mixtures, are unknown. Health statistics in New Zealand have indicated increased harm from GBL use over the last few years.