Police have arrested 12 people and seized ecstasy and amphetamines during an operation in the Coleraine area.
Drugs worth £1,800 were recovered during last weekend's raids along with a substantial sum of cash. Cannabis was also confiscated.
They were found in houses and open ground.
PSNI Superintendent Nicky Thompson said: "It should be obvious to everyone that buying illegal drugs is only lining the pockets of organised criminal gangs, who don't care how many lives they ruin or how many lives they place at risk, so long as they can reap the financial benefits.
"In the current climate of healthy living, it is difficult to understand why people are prepared to pay for illegal drugs particularly when they have absolutely no idea how they have been produced, where and in what conditions they have been stored, and what impurities and doses they actually contain."
He warned that in many cases, unconnected to this instance, peddlers kept drugs in rat-infested sewers and other unsavoury places in an effort to avoid detection.