NEW HAMPSHIRE: This week, New Hampshire became the 19th state to legalize medical marijuana—meaning that doctors will in effect be able to prescribe pot for their patients.

But people waiting for a prescription shouldn’t hold their breath: Even after medical marijuana comes to a state, it can take months to find a doctor willing to recommend the treatment.

The waiting list for an appointment at MarijuanaDoctors.com, a booking site for physicians specializing in weed, is already up to 650 patients in New Hampshire—even though doctors there aren’t permitted to sign off on pot for another year.

In Illinois, where a medical marijuana bill still awaits the governor’s signature, there are 1,800 patients on the appointment waiting list. In Massachusetts, where the waiting list is some 3,000-people long, many patients are still waiting to see a doctor since legalization took effect Jan. 1.

“The phone has been ringing nonstop,” says John Nicolazzo, COO of The Medical Cannabis Network, the parent company of MarijuanaDoctors.