The club drug Mexxy - which has been blamed for a series of deaths this year - is to be made illegal.
It is one of a series of synthetic “legal highs” - marketed online as safe alternatives to cannabis and ketamine - that are set to be outlawed following a report by the Government advisers.
They recommended banning methoxetamine, a synthetic alternative to the class C substance ketamine, a powerful tranquiliser used on animals but which has rapidly gained popularity as a designer drug.
Methoxetamine, which is known by names including Mexxy and MXE, was temporarily outlawed earlier this year. But the ban looks certain to become permanent following a report yesterday by the Advisory Council on the Misuse of Drugs (ACMD).
Prof Les Iversen, its chairman, said: “Methoxetamine is not a 'safe' alternative to ketamine…It is a dangerous and harmful drug which can cause heart problems, hallucinations and paranoia.”
The ACMD also warned that a variety of synthetic versions of cannabis on sale online could cause serious side-effects including heightened heart rate, panic attacks and convulsions.
They are sold under such brand names as Annihilation, Black Mamba, Soulman, XoXo and Love.
Annihilation has left nine people in hospital in the past three months.
Prof Iversen said: “Like many so-called 'legal highs', substances such as Annihilation can cause serious damage to your health.
“People using these substances are experimenting on themselves without knowing what the long-term effects could be.”
The ACMD first recommended generic controls on cannabis substitutes such as Spice in 2009 after it concluded they were likely to cause similar harms to cannabis itself.