It is, however, always worth repeating the warnings - especially when people think they are taking something they consider to be safe or even legal - that most often it is neither.
The latest revelation of dealers using a dental anaesthetic to 'bulk up' ecstasy pills shows they will use whatever they think they can get away with to boost their profits.
The numbers of young people being admitted to hospital after taking pills is a concern and the warnings must be heeded.
While the police are active and increasingly successful in the number and scale of drug seizures, the best way to put dealers out of business is to reduce demand for their wares.
Whether it is the recognised class A drugs of heroin and cocaine or so called legal highs or the latest 'brand' of ecstasy, dealers are becoming more imaginative in what they mix in with the drug to increase the profit margin.
The dangers are real and the warnings as important as ever.
There is no guarantee you are taking what you think you are, but one thing you can be sure of is that it is potentially fatal.