While some people rave about essential oils, others aren’t so sure. Have you ever wondered, what is the evidence that a fragrance can have a medicinal effect?

Believe it or not, there is a hospital study from Japan showing that limonene (the oil found in citrus rinds) can subtly raise the mood… and lower stress. It can also reduce stomach acid, and slightly open the airways.


People who use cannabis as a medicine often report that varieties of cannabis that have limonene in them, or so called ‘citrusy strains’, can definitely raise the mood. Are cannabis users merely exaggerating a subtle natural effect? Maybe they are, and maybe not. The pioneering Israeli cannabis researcher, Raphael Mechoulam PhD, has maintained for decades that THC can work with, or amplify, the natural effects of fragrances. He called this phenomenon the ‘entourage effect’ since compounds were acting on the brain together instead of by themselves.

As a physician, speaking with other physicians, I am surprised when I encounter automatic skepticism when I bring this topic up.

Why am I surprised? Because it’s been known for a long time that people with severe depression or psychosis often experience anosmia, or a reduction in the sense of smell. As the depression is treated, the sense of smell comes back.

And we also know that the olfactory nerve, or smelling nerve, comes right out of the front of the brain… the same location where depression occurs. The olfactory or smelling nerve is literally an extension of that part of the brain. Is it any wonder that fragrances are intimately connected with mood?

I would say that smells have a “neuroleptic effect” on the brain. They can literally cause our thinking to shift, or old memories to appear, in an instant.

This all works via G-protein coupled receptors- the same type of receptor cannabis interacts with.

Cannabis research is showing that dozens of fragrances are the reason different varieties of cannabis have specific effects. THC isn’t sedating at all by itself, since there are many ‘sativa’ varieties of cannabis with high THC which aren’t sedating at all. THC is only sedating when there is “myrcene” present, a fragrance found in nearly all of the indica varieties. Myrcene is what gives those varieties their dusky smell, and it is identical to the fragrance found in hops, and often smelled in the India Pale Ale variety of beers. For example, pillows filled with fresh hops used to be given to insomniacs in Europe, and in some places still are.

As this research piles up, it is only a matter of time before all physicians must confront these interesting facts.


– Dr. Cook