A warning about super-strong 'Skype' and 'Sprite' ecstasy pills has been issued to those attending Parklife.
It describes the pills as 'variable and high strength, 250-300mg MDMA' and advises festival goers to 'take care' and 'seek medical help if unwell'.
The Loop has also warned about other 'Sprite' pills which are three times as strong as normal pills.
According to the group the orange and white pills have been tested in Manchester. They are 'solid, tough pills with NL stamp and break line on the back' - they contain 300mg of MDMA per pill.
Again, The Loop has urged people to 'take care and seek medical attention if unwell'.
The boss of Parklife Sacha Lord has previously warned attendees not to 'overdo it'.
He said: "You've paid for your ticket and waited all this time to party with your friends and see your favourite acts.
"There's 80,000 of you in a park all there for one reason, to have the time of your lives and enjoy the music.
"Don't overdo it. Party. But party sensibly. Pace yourselves and enjoy the whole weekend. Look after each other."
Police told the Manchester Evening News that there have been 18 arrests at the two-day festival so far. Fourteen of these are reported to have been made on 'suspicion of possession with intent to supply drugs', with a number of these being related to nitrous oxide canisters.
Last night, police told the paper that so far there had been no reports of anyone falling ill.
In a statement ahead of the event, Greater Manchester Police chief superintendent Graeme Openshaw, who will be overseeing policing across the festival, said: "Our aim is to ensure the weekend is as safe and enjoyable as possible for everyone who is planning to attend Parklife.
"We are very experienced in dealing with high profile events like this and festival-goers can expect to see police officers on the ground in and around the event."
Featured Image Credit: The Loop