A school pupil required hospital treatement after purchasing drugs from another pupil at a south Manchester school.
The year eight girl purchased the drug on Wednesday 25th February however did not suffer any serious or long lasting ill-effects.
Police believe the drug was a tablet which is most likely to be MDMA.
Officers have arrested a 16-year-old boy on suspicion of drugs offences and bailed pending further enquiries.
Anyone with information is asked tocall police on 0161 856 4882 or Crimestoppers, anonymously, on 0800 555111.