If you know someone who has received a recommendation to use medical marijuana, odds are the recommendation didn’t come from a family doctor or primary-care physician.

The vast majority of recommendations in Ohio come from clinics that employ doctors solely to evaluate patients for medical marijuana, say people familiar with the industry.

Any licensed physician can apply to become certified to recommend marijuana. However, a 2016 State Medical Board of Ohio survey showed that most doctors were reluctant to recommend cannabis. Limited research on medical marijuana and the fact that the drug is still illegal at the federal level were among the biggest reasons for their reluctance. Of the roughly 375 doctors certified to write recommendations, only about half have done so. Ohio has more than 46,000 licensed doctors.

Clinics fill the gap.

"Marijuana-specific clinics fill a huge need," said Dr. Joel Simmons, who runs the Ohio Herbal Clinic, a Near East Side cannabis clinic.

While the clinics, many of which have out-of-state owners, have some critics, patient advocates say primary-care doctors are the ideal source for marijuana recommendations.

Those doctors better understand a patient’s needs and medical history, said Mary Jane Borden, co-founder of the Ohio Rights Group, which advocates for users of medicinal cannabis.

When Ohio lawmakers wrote the state’s medical-marijuana law, they hoped that family physicians would be writing most recommendations, Borden said.

Medical-cannabis users interviewed for this article, however, said their regular doctors wouldn’t write recommendations.

"I don’t think the legislators realized how long a bridge that was to cross," Borden said.

A medical-marijuana evaluation conducted at a clinic is largely a question-and answer-session in which a doctor inquires about a patient’s condition and medication history. Some doctors also perform a physical. Dr. Amish Oza, who works part time at ReLeaf Health on the Northwest Side, said part of his job is managing expectations.

"I try to tell people this is not a miracle drug," Oza said. "It will not cure cancer," but it might improve your quality of life.

Simmons said he wants to make patients understand how certain products will affect them.

"I’m letting them know the difference between CBC and THC" — cannabinoids used in medical-marijuana products.

Clinic doctors must also determine whether patients genuinely think the drug will help them or just want to get high.

"We’ve had to turn a lot of people away," Oza said.

A lack of history with other medications is a big red flag, he said, because it means they’ve never tried other treatments.

Ohio law requires patients to make their medical records available.

"You have to bring medical records to me proving that you have what you say you have," said Louis Bowman, a doctor who works with the Upper Arlington clinic Ohio Green Team.

The law also requires clinics to keep records, and Bowman said Ohio Green Team electronically catalogs all of its patients and their symptoms, and whether medical cannabis has improved their condition.

Clinics charge between $125 and $200 for an evaluation, which insurance won’t cover.

Because the clinics don’t negotiate with insurance companies, they clinics can charge whatever they want, said Emilie Ramach, founder and CEO of Compassionate Alternatives, a Columbus-based nonprofit agency that helps patients pay for medicinal cannabis.

Several clinic doctors, including Simmons, said they do their best to keep their prices reasonable.

Katherine Cottrill, 33, of Newark, has talked with patient advocates about acquiring a medical-marijuana card but says she can’t afford it. Cottrill, who suffered a chronic brain injury in 2012 and has had a series of surgeries, sought the marijuana for pain relief.

She said she would prefer to receive a recommendation from a family physician, and she considers the certification process an unnecessary barrier.

"I don’t think doctors should have to become certified to recommend it," Cottrill said. "If it’s a medical thing, then whycan’tthey just write a prescription (as they do with other drugs)?"

Mary Alleger, 31, of Reynoldsburg, had a different view. Simmons wrote her a marijuana recommendation, and she said she was grateful to find a doctor dedicated to cannabis evaluations. Alleger, who has post-traumatic stress disorder and lingering pain from a 2015 medical procedure, said she worried she would be immediately shot down if she brought up cannabis with a family doctor.

She said of Simmons, "His whole office is set up for people like us. That was the best part of the whole thing."