After a 12-year battle with debilitating abdominal conditions that forced her to stop working, marijuana has helped Lynn Sabulski feel well enough to look for a job.

Sabulski is among nearly 14,000 patients in New York state who are certified to use medical marijuana for one of 10 conditions, including her primary diagnosis, inflammatory bowel disease. Marijuana doesn't address her underlying disease, but it does relieve her painful symptoms.

Nationwide, an estimated 1.4 million patients in 28 states and the District of Columbia use legal medical marijuana for a varying list of conditions. A much smaller number of patients in 16 states use limited extracts of the plant, primarily to treat seizure disorders.

In the midst of an opioid crisis, some medical practitioners and researchers believe that greater use of marijuana for pain relief could result in fewer people using the highly addictive prescription painkillers that led to the epidemic.

A 2016 study by researchers at Johns Hopkins Bloomberg School of Public Health found that states with medical marijuana laws had 25 percent fewer opioid overdose deaths than states that do not have medical marijuana laws. And another study published in Health Affairs last year found that prescriptions for opioid painkillers such as OxyContin, Vicodin and Percocet paid for by Medicare dropped substantially in states that adopted medical marijuana laws.

In December, the New York Health Department said it would start allowing some patients with certain types of chronic pain to use marijuana as long as they have tried other therapies. The state's original medical marijuana law did not include chronic pain as an allowable condition for marijuana use, in part over concerns that such a broad category of symptoms could result in widespread and potentially inappropriate use of the controversial medicine.

Advocates for greater use of medical marijuana argue that including chronic pain as an allowable condition could result in even further reductions in dangerous opioid use.

But some physicians remain cautious about recommending the botanical medicine as a pain management tool.

Dr. Jane Ballantyne, a pain specialist at the University of Washington and president of Physicians for Responsible Opioid Prescribing, which promotes the use of alternatives to opioids for chronic pain, said she does not recommend that her patients try marijuana.

"There is no doubt marijuana is much safer than opiates. So we don't discourage its use." But in general, she said, "non-drug treatments are far more helpful than any drug treatment, and marijuana is a drug."

At Mount Sinai Hospital in New York, Dr. Houman Danesh, director of integrative pain management, suggests patients try physical therapy, yoga, acupuncture, stem cell therapy, nutrition counseling, hypnosis and behavioral health counseling before resorting to opioids or any other medications. He said lack of sufficient research to back up marijuana's safety and efficacy has kept him from adding it to his pain management tool kit, but he doesn't rule it out in the near future.

In January, the National Academies of Sciences, Engineering, and Medicine released a review of 10,000 medical marijuana studies published since 1999, showing that substantial evidence supports the use of marijuana or its extracts for the treatment of chronic pain. Existing research also supports its effectiveness in treating multiple-sclerosis-related muscle spasms and chemotherapy-induced nausea and vomiting, according to the literature review. But the study cautioned that both the positive and negative health effects of marijuana need to be studied further.

Historically, research on marijuana has been hamstrung by the Controlled Substances Act of 1970, which classifies marijuana along with heroin and LSD as illegal substances with "no currently accepted medical use and a high potential for abuse." As a result, the supply of legal marijuana that can be studied and federal funds to pursue academic research are limited.

Enacted in 2014, New York's medical marijuana law is considered among the most cautious in the nation. Americans for Safe Access, a patient advocacy group, gives the state a letter grade of C when it comes to balancing product safety and ease of access to the emerging medicine.

New York allows doctors to certify patients to purchase marijuana at a limited number of highly regulated dispensaries for the treatment of 10 conditions: cancer, HIV infection or AIDS, ALS, Parkinson's disease, multiple sclerosis, spinal cord damage, epilepsy, inflammatory bowel disease, neuropathies and Huntington's disease.

Sibulski's physician, Dr. Howard Shapiro, started certifying patients for marijuana about a year ago and quickly became a believer. He's one of only 371 doctors out of nearly 33,000 in the city registered to certify patients for medical marijuana.

As a primary care doctor who takes a holistic approach to medicine, Shapiro said trying medical marijuana was a natural for him. But he said he worried that "a bunch of druggies would start showing up." Instead, he said the patients he began seeing were all very sick and none of them appeared to be seeking drugs for fun. The improvement he saw in those first patients was remarkable, he said.

"I really think medical marijuana is the drug of the future," Shapiro said. "We're going to find out that it does a lot of things we already think it can do, but don't have scientific studies to prove it."