Oxfordshire's police say they're already having to arrest some people caught with mephedrone, even though it's not yet illegal.
It's because in some cases they can't tell whether the white powder's something which is illegal, like cocaine.
Plans have been announced to ban mephedrone - which shouldn't be confused with the heroin substitute methadone - after it was linked to the deaths of 28 young people. The plan is to make it a Class B drug, but this hasn't happened yet.
Thames Valley Police's Oxfordshire drugs co-ordinator Leigh Thompson has been telling Heart "They could turn around and say it's flour but we have to get it analysed. We can't just let people walk along the street with quantities of drugs on them, whether it's legal or illegal."
If, after questioning, the substance is found to be mephedrone, the person questioned would be free to go. They would also be able to reclaim their quantity of the drug, although in practice most decline to do so.
At least two teenagers had to have medical treatment from paramedics in Oxfordshire in March 2010 after taking mephedrone.
A 17 year old girl collapsed in Witney after mixing the drug with alcohol. A 19 year old from Wantage was given treatment after using a contaminated batch.
- produce feelings of euphoria and arousal
- make you more alert
- make you more talkative
- create feelings of empathy
- reduce inhibitions
- make you feel anxious or paranoid
- overstimulate your heart, making it beat faster
- overstimulate your nervous system, which can cause fits
- restrict your circulation, which can cause cold or blue hands and feet
- damage your nose as a result of snorting, and bring on severe nosebleeds
- bring on a low mood and a comedown after a binge
- cause death