In 1999, a young Israeli researcher named Raphael Mechoulam wrote a paper detailing the “entourage effect” of marijuana. As medical marijuana becomes an increasingly common cure for a wide range of ailments, and is being legalized in several states, the “entourage effect” is being more closely examined.

Through his research, Mechoulam and colleagues believe that it is the number of compounds in marijuana that are working together that have a sort of therapeutic effect, rather than any one single compound.

Science has yet to determine the exact roles for these different compounds, but evidence continues to point towards the fact that compounds work together rather than in isolation, a process that has been termed the “entourage effect.”

Marinol, which is pure, synthetic THC, is one example. According to CNN, when the drug first became available in the mid-1980s, scientists believed that it would have the same effect as a whole cannabis plant. However, it was soon very clear that most patients preferred taking the entire plant to taking Marinol.

After this finding, researchers began to see that other components, including CBD, might very well have a larger role than what was previously believed.

However, Marinol faced several obstacles along the way. A decade of experiments showed that whole plant extract, which was bred to have approximately the same amounts of THC and CBD as well as other components in the plant, was ultimately more effective for reducing symptoms of MS, such as pain and spasms, than medication that was made of a single compound.

Dr. Geoffrey Guy, chairman of GW Pharmaceuticals near London, explained that several individual compounds could play a role, or that it might be because of their interaction within the body, or perhaps both.

Other drugs may work well as single compounds, but synthesized marijuana from a lab could offer its most noteworthy benefits as an entire plant, as long as the “entourage effect” is left to blossom.