KUSA - When it comes to the side effects of long-term marijuana use, there is a lot doctors don't know.
LEARN MORE ABOUT LEGALIZED MARIJUANA IN COLORADO
9Health Reporter Dr. John Torres says that is because there haven't been any large studies involving humans.
However, doctors have been able to learn a few things from limited research.
Dr. John says it could take a decade or two for doctors to learn about the effects after both Colorado and Washington legalize it for a few years.
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