The scientists contend that the human body has its own endocannabinoid system which manages pain, hunger and anxiety.
Experts at the Federation of European Neuroscience Societies meeting in Vienna cited that cannabis influenced many different areas in the brain, nerves and immune system.
Research shown at the conference using a plant-based cannabinoid, anandamide, worsened epilepsy-like condition in rats.
Doctors counter that other studies in animals and humans have seen multiple sclerosis patients benefiting from cannabinoid medicines.
Professor David Baker, of the Institute of Neurology at University College London, told BBC: "There is a benefit of moving from agents from illegal plant based medicines to looking at how we use pharmaceutical medications to target the benefits of cannabinoids, but reduce the well known adverse effects."
The only cannabis-based drug currently used in the U.K. is a drug called Sativex used for the treatment of multiple sclerosis.
