Drug charity The Loop says the strong pill, made up of N-ethyl-pentylone, can cause paranoia and keep consumers up for 72 hours straight.

ALERT: Blue 'Punisher' pills (a skull logo in a superman shape) tested today at @LSTDBristol found to contain >300mg MDMA. This is 3-4 times a typical expected dose. Common harm reduction advice is start with a quarter and regularly sip water! #startlowgoslow pic.twitter.com/T4BsROy0jN — The Loop (@WeAreTheLoopUK) May 26, 2018

Drug safety charity The Loop has issued a warning about a drug found at Parklife festival last weekend.N-ethyl-pentylone, which resembles MDMA in appearance and smell, was discovered when a festivalgoer brought the drug to The Loop's on-site testing facilities . The Loop warns that, despite it having similar initial effects to MDMA, it can cause "anxious stimulation," "severe paranoia," "temporary psychosis" and insomnia, which could last up to 72 hours.N-ethyl-pentylone is three times stronger than MDMA, although the overall MDMA-like effects are less intense, according to a report . Because of this, users are likely to take more of the drug, which could lead to an accidental overdose. Last year, The Loop wrote that it had been noticing N-ethyl-pentylone circulating at festivals in drugs mis-sold as MDMA.When asked about whether N-ethyl-pentylone was falsely sold as MDMA at Parklife, The Loop's director Fiona Measham told: "We don't know for this festival because it was a back-of-house lab without direct access by the general public. It's a good question and a good example of why we also need front-of-house testing services that directly engage with the public."Measham then spoke to the effectiveness of these on-site testing facilities at deterring people from consuming drugs that are potentially more dangerous than they anticipated: "At previous festivals, we have found that generally only a very small number go on to replace the drugs. This is because often they have no money left for more drugs, but also, they have been ripped off, they have found out some of the very unwelcome drugs mis-sold as MDMA and don't want to take that risk again."The Loop also tweeted a warning about "Duracell" pills , which they tested to be about two to three times stronger than the average adult dose of ecstasy. These were also in circulation at Parklife.These increased drug warnings come after two people died at Mutiny Festival in May. Blue "punisher" pills were found at Bristol festival Love Saves The Day, which led organisers and The Loop to put out a warning on social media. They were also discovered at Parklife