Steven Baxter, 26, died after taking heroin - a drug he had been addicted to for a number of years.
Prior to his death he had weaned himself off the class A substance by enrolling on a methadone programme.
However, a relapse proved fatal, as the detox had reduced his tolerance to the drug and made him more susceptible to overdose, Teesside Coroner’s Court heard.
He was found unresponsive by his mum at their home in Redcar , on November 18, last year.
Tests showed he had levels of morphine in his blood lower than those normally associated with fatality.
In a statement, Mr Baxter’s sister, Samantha Baxter, told how he had spent the majority of his adult life as a drug user.
She said: “He used a variety of substances including amphetamines, cannabis, legal highs and heroin, the last of which he was addicted to for about three years.
However, she told how her brother had been working through a methadone programme to come off the drug, which he had completed in October last year.
“To our knowledge he was still using recreational drugs when he could afford them,” Ms Baxter said.
The inquest also heard how his girlfriend died two years ago of a suspected drug overdose - which he never seemed to recover from.
In the run up to his death Mr Baxter was in a good mood and cheerful, the court heard.
However, his mum said his mood changed when she believed he had gone to buy heroin.
It was the following day that she found him unresponsive.
There were no suspicious circumstances surrounding his death.
