A young builder died in agony after he took diet pills containing a lethal chemical, an inquest has heard.
Vaidotas Gerbutavicius, 21, swallowed several of the illegal tablets which contain a chemical used in explosives.
He took them with rum and vodka and then told his dad "I'll be dead in an hour".
He also told his dad "no one could help" and then complained of feeling a "burning sensation" before he was rushed to hospital in Leytonstone, east London, where he tragically died four hours later.
An inquest into his death heard how the previously overweight builder had purchased dinitrophenol (DNP) on the dark web to help him slim down.
The drug was marketed as a diet pill in the US in the 1930s but has since been made illegal in the UK.
It can cause high temperatures, nausea, abdominal pain, seizures, and organ damage and is classified as an explosive under UN regulations.
The hearing was told Vaidotas suffered a cardiac arrest when he was taken to hospital on March 10, 2018.
His temperature was also so high nurses used up all their ice packs attempting to cool him down.
He later became "hysterical" and complained of feeling pain in his "head and all over my body".
Senior coroner Nadia Persaud branded the drug a "poison" as she called for a Home Office review into the sale of DNP.
She said: "The current legislation is wholly inadequate and in no way an appropriate means by which to deal with offences that can result in the deaths of those who consume DNP.
"Those affected are often young and vulnerable people."
The hearing was told Barry Wright, from Northern Carolina, US, who sold the drug to Vaidotas was caged for seven years in February this year.
Since 2017, at least 30 people have died from taking DNP in the UK, the court was told.
Dad Andrius said he does not want any family to have to go through the pain his has suffered.
He said: "Before this, I had never heard of DNP. I had no idea such a thing existed in the world.
"There have been so many deaths in recent years, but people will keep on dying unless the law is changed and the Government starts to effectively tackle the sale of this deadly substance.
"This cannot be allowed to continue."
Ruling out a verdict of suicide, Ms Persaud declared the cause of his death as consumption of DNP, calling it an "extremely harmful substance" which has "no antidote available".