Nearly 200 people have been arrested in the first three months after a blanket ban on drugs formerly known as "legal highs" came into force.
Hundreds of shops have also either shut down or stopped selling "psychoactive" substances.
Laws criminalising the production, distribution, sale and supply of the drugs were introduced from May 26 after they were linked to dozens of deaths.
The first national figures since the Psychoactive Substances Act took effect showed that police have so far arrested 186 individuals.
In addition, 308 retailers are no longer selling the drugs and 24 head shops have closed down altogether.
Commander Simon Bray, National Police Chiefs Council's lead on New Psychoactive Substances (NPS), also said the Metropolitan Police had seized nearly 14,000 nitrous oxide cannisters since the Act commenced. Nitrous oxide is commonly known as laughing gas.
Bray said a lot of premises were either shutting themselves down and "diversifying" before the act took effect, or in some cases, police forces were using other legislation to try and close them down.
In relation to online activity, he said that some websites were now offering "ban-friendly" items, while others had changed domain names and moved abroad.
The National Crime Agency had taken action to shut down websites found to be in breach of the ban, and was working with international partners to address sites based overseas, the Home Office said.
Under the previous regime, authorities were locked in a game of cat and mouse in which manufacturers produced substances with a slightly altered chemical make-up almost immediately after the previous version was banned.
Bray said: "The law can't be outwitted in that sense any more because if it's psychoactive, it's psychoactive full stop.
"Therefore there is less incentive to have this sort of arms race-type approach whereby people are inventing new substances all the time simply to outwit what we do."
Although it was difficult to draw firm conclusions yet about the impact on use of the drugs, Bray said: "Intuitively I think it must have had an effect. It will certainly make it less easy for the casual first-time user to get involved in this sort of stuff."
One of the key issues previously was the availability for people who would be "lulled into buying these things" thinking they were legal and therefore safe, and also accessible, Bray said.
He added: "That aspect is now made much more difficult. Therefore there's a whole range of people who will not be persuaded to take these things anymore who previously would. So it's reducing danger for some."
Under the Act, offenders can face up to seven years in prison, while orders can be issued to shut down head shops and online dealers.
Safeguarding minister Sarah Newton said: "These dangerous drugs have already cost far too many lives.
"I'm encouraged to see that - three months in - police are using their new powers to take dealers off our streets and that so many retailers have been denied the chance to profit from this reckless trade. These drugs are not legal, they are not safe and we will not allow them to be sold in this country."
NPS saw an explosion in the popularity of "legal highs" on the drug scene around 2008/09. They contain substances which mimic the effects of "traditional" illegal drugs like cocaine, cannabis and ecstasy.