While more research is needed, scientists say the brightest prospects for the medicinal benefits of cannabis so far may lie in more complex combinations of its compounds. CBD, the non-psychoactive medicinal ingredient found in the marijuana plant, has been credited with relieving pain and inflammation, reducing epileptic seizures, quelling anxiety and insomnia, combatting some forms of cancer and even tempering acne.

Discovered in 1940 and thought at first to have no pharmaceutical value, today CBD-short for cannabidiol-can be found in everything from topical creams to capsules, tinctures to lip balm, infusing knee braces to beer.

"The problem for me is there are so many outrageous claims being made, "said Timothy Caulfield, University of Alberta health law expert, health trend tracker and host of the television series A User's Guide to Cheating Death.

"Even GOOP (Gwyneth Paltrow's health and wellness company) has jumped on the cannabis bandwagon, and they're pushing it to the wellness thing that we should be taking for our general well-being.

"There is no research to back that up right now, and I will remove skeptical it will ever emerge," said the author of  Is Gwyneth Paltrow Wrong About Everything? When asked if an abundance of encouraging anecdotal reports should count for something, Caulfield is unequivocal.

"Nope," he said. "Testimonials and anecdotal reports may suggest research, but it is never good evidence." The scientific process is specifically designed to overcome the biases inherent in anecdotal evidence. "Anecdotal data is just a bunch of stories. It happens so often that when you do the actual clinical trials on this stuff, the results are underwhelming."

Evidence so far 'underwhelming.'

Underwhelming is precisely what Michael Allan, director of evidence-based medicine in the U of A's Department of Family Medicine, found after completing a review of scientific literature for Canadian Family Physician.

While conceding there is "reasonable evidence" that cannabis can help with nausea and vomiting after chemotherapy and may improve spasticity in conditions like multiple sclerosis, there is little to suggest cannabinoids help with pain, and "if they do, it is a neuropathic pain 

"Medical cannabinoids have been advocated for an extensive variety of conditions, from glaucoma to cancer," wrote Allan. "Unfortunately, bias is pervasive throughout the medical cannabinoid literature, including in randomized controlled trials. This is compounded by poor reporting in the media, with 79

However, some researchers say the anecdotal promise of medical cannabis is too strong to ignore, and are poised to go after supporting evidence. Some of that clinical proof is already starting to emerge as more researchers take up the quest.

More to it than CBD

U of A pharmacy researcher Raimar Loebenberg said he is eager to contribute to the nascent body of clinical data. I have started exploring the analgesic properties of CBD topical creams to see if the hype is justified.

Producers of the cream claim it relieves muscle soreness. Some reports even suggest it can be effective in combatting skin cancer, said Loebenberg. One big problem with unregulated CBD products, he said, is unreliable quality and inconsistent dosing. Some producers may also fail to recognize the pharmaceutical complexity of the marijuana plant and the way in which its cannabinoids interact with the endocannabinoid receptors in our bodies.