A man has been arrested after fake ecstasy pill 'Rockstar' left seven in hospital.
Strathclyde Police said the 18-year-old was detained in custody on Monday in connection with "alleged drug offences".
He is expected to appear at Airdrie Sheriff Court on Tuesday in connection with the allegations.
Police had issued a warning over the pills after seven people from the Lanarkshire region were admitted to hospital once they had consumed the drugs.
Strathclyde Police issued a warning to the public to beware the "potentially deadly" pills, which can be either red or yellow in colour and carry the impression of a star on them.
Officers said the contents of the tablets were unknown but could be a cocktail of various other substances. The force said it was working with health officials and medical staff to determine the make up of the tablets and their origin.
Chief Inspector Fraser Lamb of Strathclyde Police said: "These substances are unreliable, unpredictable and potentially very dangerous. Users may believe that they have taken ecstasy, and it is very likely that they will suffer from a significant negative reaction.
"Symptoms reported recently include increased heart rate, elevated core temperature and seizures. These pills are not covered by any form of quality control and this is supported by past forensic analysis.
"Users need to be aware of the dangers and understand the potentially devastating effect these pills can have on their health."