North Dakota's new law was patterned after rules in Oklahoma, where tighter restrictions brought a dramatic decline in the number of meth labs discovered by police, Stenehjem said.
At least seven other states have some provision to keep records or report sales of pseudoephedrine, and 11 others have sales limits for chemicals used to make meth, according to a National Conference of State Legislatures tally.
The count is likely greater now after action in several statehouses this year, said Blake Harrison, an NCSL researcher who tracks the regulations.
"It's been in the last five years that states have been addressing the precursor issue," he said. "States did a good job of putting the restrictions in place, but they're sort of fine-tuning them now."
Lawmakers in Minnesota's state House endorsed a measure that would require a prescription to buy the tablet forms of medications containing pseudoephedrine, but the measure still faces additional legislative review.
"That would be the strongest approach, I think, if that passed," Harrison said.
Dennis Johnson, vice president of the North Dakota Pharmacists Association, said the benefits of controlling meth seem worth the inconvenience.
"How do you get a handle on this meth thing? Everybody's grappling with how to do it," he said.
Johnson predicts that most of the opposition will come from grocery stores and truck stops rather than pharmacists, who continually look for more ways to talk with patients about their health.
"It might inconvenience a few people who use it all the time, but there's plenty of studies out there that say they should consult a health professional before they grab some of these over-the-counter things," he said.