Two painkillers are to be reclassified as class C controlled substances amid concerns people are becoming addicted to them and misusing them.
The drugs – pregabalin and gabapentin – are also used for epilepsy and anxiety.
The move, announced by the Home Office, means it will now be illegal to posses the drugs without a prescription and it will be illegal to supply or sell them to others.
The government acted after experts said tighter controls were needed.
The Advisory Council on the Misuse of Drugs raised concerns about the drugs – amid reports of a rising number of fatalities being linked to the drug.
The law change will still mean the drugs are available for legitimate use on prescription, but there will be stronger controls in place.
Doctors will now need to physically sign prescriptions, rather than electronic copies being accepted by pharmacists.
It puts them on the same legal footing as tranquilisers and ketamine.
Victoria Atkins, Minister for Crime, Safeguarding and Vulnerability, said the government decided to change the law after receiving expert advice.
"Any death related to misuse of drugs is a tragedy" she said.
The new measures will come into force in August.
It comes as Public Health England is reviewing what it says is the "growing problem" of prescription drug addiction.
NHS data has suggested one in every 11 patients in England is being prescribed medication which could be addictive, or difficult to come off.
This includes sedatives, painkillers and antidepressants.