In 2010, it was the UK's fourth favorite 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.
And spent an afternoon snorting angina medication.
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.
What, exactly, is so wrong with getting high in 2016?
As of today, legal highs are no longer legal in the UK. We spent the night with some salesmen and users to get their take on what comes next.
Scientists and policy experts have raised concerns about the UK government’s broad ban on “psychoactive substances.”
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 are stuck in the throes of addiction.