Monday marks the first time patients with Illinois-issued ID cards can buy medical marijuana legally in the state.

More than 3,000 patients now have admittance to these eight dispensaries, access that was determined by conditions approved by the Illinois Department of Public Health. Some of these conditions include chronic post-operative pain, post-traumatic stress syndrome, and osteoarthritis.

But osteoarthritis, according to a new scientific review, may not actually be helped by marijuana at all. The evidence is scant, reports rheumatologists in the journal Arthritis Care & Research — and they can’t in good faith recommend medical marijuana as a treatment to their patients.

The team behind the review analyzed medical literature spanning back to the 1940s and only found four studies that looked at the relationship between medical marijuana and rheumatic diseases like osteoarthritis and rheumatoid arthritis. These studies were short in duration and lacking in subjects — there wasn’t a single controlled study examining herbal cannabis in the rheumatology patient population.

“In the context that rheumatic diseases, including osteoarthritis, are very common, these studies provided limited information,” said review lead Dr. Mary-Ann Fitzcharles in a press release. “We cannot draw any conclusions regarding efficacy or side effects — especially long-term side effects — associated with cannabinoid therapy.”

It’s common for American states that have legalized medical marijuana to have rheumatoid arthritis and osteoarthritis as conditions that will allow you to have a medical marijuana card. In Australia and the United Kingdom, one-third of marijuana users do so to treat arthritis pain, while “severe arthritis” is the reason 65 percent of Canadians are authorized to possess medicinal cannabis. Yet two-thirds of Canadian rheumatologists admitted that they aren’t confident in their knowledge of cannabinoid medical use, while 70 percent stated in the same survey that they don’t think there is purpose for herbal cannabis when treating rheumatic symptoms.

While there is good evidence that medical marijuana can help with other chronic pain conditions like cancer, notes Fitzcharles in a 2014 precursor to her most recent review, these pain types have a different underlying mechanism from the pain that happens with rheumatic diseases. It’s bad science to say that because marijuana helps some pain, that it will help this specific pain.

“Simply acceding to patient demands for a treatment on the basis of popular advocacy, without comprehensive knowledge of an agent, does not adhere to ethical standards of medical practice,” writes Fitzcharles in her 2014 paper. “We believe that herbal cannabis should not at this time be allowed exceptional status as therapy.”

That opinion still holds today but Fitzcharles and her fellow researchers emphasize another plea in their most recent review: The scientific community need to produce more research to determine if medical marijuana can help people suffering from rheumatic conditions. The evidence so far doesn’t say yes — but it doesn’t say it’s not possible either.

Photos via Giphy, David McNew/Getty Images