Party drug meow-meow is now as popular as cocaine among 16 to 24-year-olds, according to Home Office statistics.
Meow-meow, or mephedrone, was recently classified under the Misuse of Drugs Act after it was linked to a spate of deaths.
The British Crime Survey for 2010/11 estimates that 8.8% of adults aged 16 to 59 had used illicit drugs, almost three million people.
The data showed, as in previous years, cannabis was the most commonly used drug for adults, with 6.8%, around 2.2 million people, using it.
About one million adults used a class A drug in the last year, the statistics suggest.
But the most striking development from the research was that 4.4% of 16 to 24-year-olds had used meow-meow - the same level as powder cocaine.
Crime prevention minister Baroness Browning, said: "While the level of drug use remains at its lowest level since 1996, there are still real concerns about cocaine.
"Also so-called 'legal highs' present new challenges. These substances are marketed as legal or safe when often they are neither. That is why we have introduced legislative proposals to ban the import and supply of harmful new substances.
"The Government's focus is not only on helping drug users to beat their habit but also on stopping young people from using drugs in the first place. Alongside this, we are working closely with police and other agencies at home to prevent drugs coming into the country to reduce supply and demand."
The level of any drug use was highest among the 16 to 19 age group (23%), while class A drug use was higher for 20 to 24-year-olds (8.2%) than all other age groups.