Mexican drug cartels are taking over small-scale Breaking Bad-style labs and becoming the main suppliers of meth amphetamine in the US.
The number of labs run by small gangs of criminals or individuals has fallen from almost 24,000 in 2004, to 11,573, according to recent Drug Enforcement Agency data.
Methamphetamine lab busts and drug seizures in Tennessee are down by 41%, according to the Tennessee Bureau of Investigation.
Other states plagued by meth production have seen a similar drop.
However with figures showing the levels of use of the drug remaining steady, experts and law enforcement officials believe that Mexican cartels are stepping in to make up the supply.
In the hit TV show Breaking Bad, high school chemistry teacher turned drug dealer Walter White produces crystal meth from the back of a camper van turned into a makeshift lab.
Drug seizures along the Mexican border have also spiked, with figures obtained by VICE showing that in California the feds captured more than three and a half metric tons of the drug in 2013, up from 2012's half a ton, and smaller amounts in previous years.
Sergeant Jason Grellner of the Franklin County Sheriff's Department though said that the success in closing down labs was freeing up police resources to target supply routes.
"The good thing for the communities is this: meth is a horrible drug that decimates the user, and the labs are manpower intensive to destroy," Grellner told VICE News. "With [mom and pop] labs, it's like swatting mosquitoes in July. And now we can go back to working drugs in a traditional and effective manner."
Grellner told the website that a number of factors explained the decline of small-scale meth production in the US.
Firstly, he said, cartels had improved the product, with cartel chemists transforming the production process to ensure greater purity, by altering one of meth's isomers into D-methamphetamine, the component of the drug which causes a high.
"[The cartels] spent a lot of money in research and development," Grellner said.
Previously, US producers had an advantage by being able to easily access pseudoephedrine, a key meth ingredient found in a once-commonly available cold medication. The medication is not available in Mexico.
However, with the medication increasingly difficult to obtain in the US with tighter regulation constricting its scale, cartels have the advantage.