In 2010 it was the UK's fourth favourite substance; nowadays it's used almost exclusively on the chemsex scene.
A new bill banning any and all "psychoactive substances" was the direct result of a moral panic started by the red tops.
This weekend one of the first jail terms for selling NOS was handed down, a pig ran around Ipswich to 'make friends' and more.
The stats are in about what the bill has achieved.
When the tabloids write horror stories about drugs such as mephedrone or laughing gas, searches for how to buy those drugs go through the roof.
What, exactly, is so wrong with getting high in 2016?
From today, legal highs are no longer legal. We spent the night with some salesmen and users to get their take on what comes next.
An interview with the man who owned the UK's biggest legal high wholesale business.
Days after a study suggested synthetic cannabis can be as physically addictive as heroin, we met some users who stuck in the throes of addiction.
The Home Office has finally announced when it's going to start enforcing its blanket ban.