The government is to look urgently into whether to ban the legal drug mephedrone following the deaths of two teenagers who had taken it.
BBC News website readers give their experiences of the drug:
Having taken other recreational drugs in the past, I had some at a festival last year and it completely wiped me out.
I found it stronger and a lot more potent and psychedelic than any other substance I have used - including LSD.
I completely zoned out for a period of time. I didn't know where I was. I went the toilet and was sick. Later I was sick in a field. I started panicking. I just assumed it wouldn't be that strong as it is legal. I woke up the next day with the worst hangover I've ever had.
From my experience people think it is safer because it is legal and very easy to find. It's also very cheap - you can buy 3 grams for £10.
I know a group of people who are basically junkies now. They take it all the time and are basically addicted to it. They also sell it over the internet.
The new generation are cleverer than the authorities - which spent so much time trying to clamp down on cannabis. The kids have just found a new drug that the government didn't even know about.
We should either ban this drug, or, more sensibly, make all drugs legal so the government can regulate them properly.
GAIL, SOUTH OF ENGLAND
I have both personal and professional experience of young people using this drug.
My son who is 26 has used all sorts of substances in the past except heroine. He came to me in December totally hooked on Mcat [mephedrone].
It is awful to see your son in this mess. It's the first time that he has started looking like a druggie - he is so thin and doesn't look after himself.
He said he has never known anything so addictive. He has palpitations and doesn't sleep for days.
He is getting help now but it is a struggle when this substance is readily available.
I work as a personal tutor, predominantly with young males, and it is a substance that these young students are choosing to use, not seeing the dangers or impact on their lives, because it is "legal".
It seems like every day I am dealing with a student who has got hooked on M-Cat and it totally takes over their lives.
I feel very strongly that something needs to be done now.
The names of the people appearing in this article have been changed.