The short answer is we really don’t know, as we have not had the time to fully study these substances. But we do know that they ‘mimic’ other drugs and they take certain routes around your brain to create the desired effect.
We do know that if people who do not get sleep or their brain does not ‘rest’ they can suffer issues around ‘drug induced psychosis’, this is not pleasant to watch. We are aware that there has been an increase in people attending mental health facilities due to their use of ‘NPS/Legal Highs’.
We also know that people have attended hospital due to overdose of some of these substances, getting treated for overdose in a hospital is not a pleasant experience for the individual or their family. Because it’s legal does not mean it’s safe.