New Psychoactive Substances (NPSs) are molecules that contain “non-illegal” compounds though exhibiting psychoactive effects to consumers. They are recently evolved to replace the illegal drugs such as cocaine, methamphetamine, cannabis, etc.  The United Nations Office on Drugs and Crime (UNODC) categorise the main substances of NPS includes aminoindane, synthetic cannabinoids, synthetic cathinones, ketamine, phyncyclidine-type substances, phenethylamines, piperazines and tryptamines 
The consumption of NPSs can be associated with short and long term health risks. Generally speaking, they are acute psychosis, seizures, aggression, hallucination, euphoria, irregular heartbeat, twitches and tremors and even intoxications. Another serious problem with NPSs is their purity and composition are usually unknown which often cause dangerous toxicity  Long term use of NPSs can cause tolerance and dependence. Withdrawal effects can trigger anxiety, aggression or craving for the drugs.
In recent years, NPSs have been introduced to the illicit market in a form of bath salts to avoid the claiming of drug abuse and legislation  In some cultures, in order to serve their own psychotropic effects several herbal products whose characteristics included in NPSs are utilised without being scheduled as illicit drugs. They are, for example, Hawaiian baby woodrose and Voacanga Africana  Another example of misleading information about NPSs is energetic supplement which contain sildenafil acting similar to Viagra. It was reported they claim themselves containing natural substances with no side effects 
Due to the lack of registration and the appearance of innocent form of drugs, a significant raise in young generations are attracted. Reports showed there is an increase use of NPSs had led to disruption in mental states and even associate with acute intoxications and deaths 
Figure 1. Poster from UNODC summarising the common NPSs available in the market and labelled as “non-illegal” or “natural with no side effects”
From 7th October 2013, NSW Police Force had changed the New Psychoactive and Other Substances Acts which mainly stated that the “supply, manufacture or advertisement of any psychoactive substances is prohibited in NSW” It was announced that 45 new psychoactive substances were added to the Schedule of prohibited drugs and plants. Penalties apply of up to $48,000 or 4 years in jail. A person convicted of a drug offence can receive a criminal record, which can lead to difficulties in getting a job, health insurance, credit and/or visas for overseas travel 
Nevertheless, NPSs are not under international control. The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) (2016) stated that NPSs are not categorized in the United Nations Conventions of 1961 or 1971 where cocaine, cannabis and other psychoactive drugs are listed  Another main concern with NPSs is the lack of toxicological screening of biological sample which make it difficult to evaluate the rapid evolution of new compounds to the market  As a result, the identification of drugs is a challenge and further legislation can be delayed and confused. NPSs can be “hidden” or unlabelled in a number of products with the claim “not for human consumptions”. In fact, these products neither state the molecules nor unwanted effects caused.
In conclusion, it can be clearly seen that further research and urgent development for screening method are necessary in the new evolution of psychoactive drugs. Instead of publishing the prohibition of compound’s name, the laws can address the effects or generic chemistry of the drugs.
 Donata, F. et al., 2013, New Challenges and Innovation in Forensic Toxicology. Focus on the “New Psychoactive Substances”, Journal of Chromatography A
 United Offices of Drugs and Crime, 2017, Early Warning Advisory of New Psychoactive Substances, viewed 9th May 2017 <https://www.unodc.org/LSS/Page/NPS>
 J.M. Prosser & L.S. Nelson, Journal of Medicinal Toxicology 8, pg 33
 C.D. Rosenbaum, S.P. Carreiro, K.M. Babu, 2012, Journal of Medicinal Toxicology 8, pg 15
 B.J. Venhuis, D. de Kaste, 2012, J. Pharm. Biomed. Anal.
 NSW Government, NSW Police Force, 2016, New Psychoactive Substances and the Law,viewed 9th May 2017 <http://www.police.nsw.gov.au/community_issues/drugs/new_psychoactive_substances/new_psychoactive_substances_and_the_law)>
 European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), 2016, What are new psychoactive substances?, viewed 9th May 2017, <https://www.youtube.com/watch?v=7jF6S6YNC3U&list=PLVoVaLKfvFDB7bnSsnKj9aLFEC2h3xB8f>