A 'very vulnerable' Chesterfield teenager died after swallowing a single ecstasy tablet, an inquest heard.
James Yates, of Highfield Lane, took the drug at a festival and later passed away in hospital after medics worked through the night to try and keep him alive.
He was just 19.
Giving evidence at the town's coroners' court on Wednesday, Dr Mark Withers, a consultant anaesthetist at Chesterfield Royal Hospital, said Mr Yates was admitted to A&E on the evening of July 23 last year.
"He was in a pretty bad way," Dr Withers added.
"Everything was done to try and give him a chance to survive - but as the evening went on it sadly became clear that James's death was probably inevitable."
Dr Withers said Mr Yates died at 6.35am on July 24 because of the 'complete failure of his body as a result of the ecstasy overdose'.
Pathologist Dr Andrew Hitchcock told the inquest that the cause of Mr Yates's death was 'multiple organ failure due to ecstasy toxicity'.
The court heard how foster carer Jacqui Kirk looked after Mr Yates when he was aged between 15 and 18.
She said: "He was very complex and very vulnerable.
"He would do anything for friendship.
"If someone said 'take these, you'll like them', he'd have taken them.”
She said Mr Yates had only told her once that he had taken drugs - but he said he did so 'accidentally'.
Mr Yates chose to leave Mrs Kirk's care after he turned 18 and ended up staying with a friend.
After Mr Yates died, his sister Natalie Taylor paid tribute to her brother.
She told the Derbyshire Times: "James was a very happy person who just wanted to have fun.
"He was very vulnerable due to his foetal alcohol spectrum disorder and very easily led.
"None of his family and friends expected this to happen at all, not ever."
She added: "For anyone thinking about getting involved with drugs, please don't.
"James is proof that drugs can kill.
"He wasn't a drug addict, it only takes one time."
Coroner Peter Nieto is expected to conclude the inquest on Thursday afternoon.