Manchester police have renewed their warning about taking ecstasy as a 16-year-old boy fights for his life in hospital after taking it.
Police said they were "concerned" that the force was dealing with another young person falling ill as a result of taking the drug in recent weeks.
They said the teenager remains in a critical condition after overdosing on the ecstasy pills known as "Rockstar" on Saturday morning at a private house party.
Police were called to the address on Elm Road in Oldham shortly before 4.25am.
In the past month, GMP have issued several warnings about the dangers of taking the party drug after one teenage girl died and two women were taken to hospital after all taking variations of ecstasy.
Seventeen-year-old Faye Allen, from Liverpool, died after taking a pink pill called "MasterCard", believed to have contained double the dose of MDMA normally found in an ecstasy tablet.
She had been at the Victoria Warehouse in Trafford, Greater Manchester.
Days later, two 21-year-old women from Stockport were taken to hospital from a Manchester nightclub in Princess Street after an adverse reaction to ectasy pills - believed to be MDMA tablets dubbed "Lego".
"Our repeated warnings can only do so much. We want young people to look at the devastating effects ecstasy has had on other young people, even in the past month in Greater Manchester, and think twice
Sergeant John Coleman from GMP's Oldham Division said that young people were taking the drugs without thinking of the consequences.
He said: "I am concerned that GMP is dealing with another young person who has taken ecstasy and ended up fighting for his life as a result.
"Over the past month we have had the death of a 17-year-old girl and the hospitalisation of two young women all after taking a variation of ecstasy.
"Our repeated warnings can only do so much. We want young people to look at the devastating effects ecstasy has had on other young people, even in the past month in Greater Manchester, and think twice.
"Young people are taking these drugs without considering the consequences. These drugs are illegal for a reason. They ruin people's lives."
He added that his thoughts were with the 16-year-old boy and his family and friends and investigations are under way as to how the teenagers got hold of the drugs.
He said: "The boy and his friends took a type of ecstasy known as Rockstar. Obviously when the night began the youngsters did not expect to have their friend in a critical condition by morning.
"Police will now be investigating how the teenagers got hold of these class A drugs and we will be working hard to find those who supplied them."
Anyone with information about where the drug may have come from is asked to contact police as soon as possible.