Coffee and caffeine creates a mellow yet productive kind of equilibrium. But, there’s more to the relationship between cannabis and coffee than you might think.

Plenty of weed enthusiasts know that the best way to start your day is to blaze up with a fresh cup of coffee (we’ve already found a number of different ways to incorporate cannabis into our morning joe). But why exactly is combining weed and coffee such a wondrous thing?

Most people would probably answer this question by saying something about the complementary effects of the two substances when they’re combined. The caffeine gives you energy, while the cannabis takes the edge off of the caffeine, which creates a mellow yet productive kind of equilibrium. But, there’s more to the relationship between cannabis and coffee than you might think.

The link between cannabis and caffeine has to do with your metabolism. A study published in the Journal of Internal Medicine last year found that increased coffee consumption led to a drop-off of blood metabolites in the endocannabinoid system (ECS). The ECS helps regulate a lot of important bodily functions like mood, appetite, stress, inflammation, and sleep.

The lead author of this study, Marilyn Cornelius, explains that the endocannabinoid metabolic pathway is an important part of how the body regulates stress. An increase in stress, like that which occurs from consuming large quantities of caffeine, results in the destruction of endocannabinoid neurotransmitters. Cornelius says this could be the body’s attempt to bring stress levels back down to equilibrium.

As you consume more caffeine and your endocannabinoid neurotransmitters deplete, less of them reach the ECS. This is because the ECS’s primary goal is to achieve and maintain homeostasis, or internal balance, within the body despite changes happening in the external world. Your body produces endocannabinoids naturally, which it then sends out to different parts of your body to make sure everything is balanced and functioning properly. In this way, your body’s endocannabinoids act like THC and CBD, but they have a much shorter and lesser effect than do actual, plant-derived THC and CBD.

When you use cannabis, however, the opposite of this phenomenon occurs. The plant-derived cannabinoids that enter your body when you use cannabis act on the body by imitating the endocannabinoids your body produces naturally. These are the agents responsible for the recreational and medicinal effects of cannabis.

Whether cannabis use offsets the loss of endocannabinoids due to stress/caffeine intake is unknown, Cornelius says, but logic would suggest that it’s entirely possible this is the case. That cannabis and caffeine impact each other in some way is undeniable. Until science catches up with the rest of us who enjoy a strong cup of coffee with our wake n’ bakes, though, we can only speculate as to the physiological effects of ingesting both substances together on the body.

But, whatever the physiological implications, the magical feeling after toking up and enjoying a nice cup of coffee is enough for this stoner to keep with the cannabis-and-caffeine combo to start each day.