Increasingly, medical marijuana is being considered as an alternative treatment to manage chronic pain. But with so many strains of cannabis available at Pennsylvania dispensaries, which is the most effective?

A partnership between the University of the Sciences, regional marijuana retailers, and an app called Releaf eventually may provide an answer.

Nearly 70,000 patients across the nation are already using the free Releaf app, according to Tyler Dautrich, Releaf’s Philadelphia-based chief operating officer. These users anonymously report their experiences with different varieties of cannabis to treat various ailments.

In Pennsylvania, state residents who suffer from any one of 23 serious medical conditionsare eligible to apply to become part of the state’s medical marijuana program and buy cannabis through state-approved dispensaries. Those conditions range from cancer to PTSD to anxiety and pain. Recommendations to use cannabis are written by a patient’s physician.

The USciences study will focus on pain, the condition that most patients report to their doctors when seeking a cannabis use recommendation.

Because cannabis remains illegal under federal law, double-blind placebo-controlled clinical trials are impossible to conduct. [Read more at The Philadelphia Inquirer]