![Picture]( https://cdn.pixabay.com/photo/2017/11/03/19/06/herb-2915337_960_720.jpg) Drugs. In one way or another, they’re a part of everyone’s life. Some take illegal drugs, some legal ones, some take drugs that are not necessarily considered drugs. But be it cocaine, alcohol or sugar, it all has an effect on our body, good or bad. @techslut asked me to write a post about the endocannabinoid system and cannabis. I thought I already knew plenty about this and wouldn’t need to do much research. I was wrong. The endocannabinoid system is incredibly complex. It influences cognitive processes, fertility, appetite, pain, memory, mood and might even contribute to what is known as “runner’s high”. At first, it was believed that there are only two receptors for the system, CB1 (found mainly at presynaptic sites) and CB2 (mainly found on immune cells). And then … they discovered more. Isn’t biology great. To simplify this post, I will try to concentrate on CB1 and CB2 with emphasis on CB1. CB1 is, as already mentioned, located at presynaptic sites. What does that mean? _{_{_{_{_{_{_{_{_{_@suesa}}}}}}}}} A synapse where neurons are in contact with each other and transmit information. Usually, the order is neuron 1 releases neurotransmitters via the presynaptic side, those pass through the synapse and enter neuron 2 at the postsynaptic site. Neuron 2 then transmits that information. ![](https://cdn.pixabay.com/photo/2014/04/02/11/17/science-305773_960_720.png) For CB1, the transmission is *the other way around*! The transmitter, endocannabinoids, comes from neuron 2 and enters neuron 1 through the receptor. The result is that neuron one takes up less calcium, which plays a significant role in the release of neurotransmitters. Long story short: endocannabinoids cause neuron 1 to transmit less information. That can cause pain relief. It’s no surprise that the endocannabinoid system can be found in most, if not all mammals. Now, endocannabinoids are produced by your body (*endo* comes from the Greek *endon* which means *within* or *internal*). But they’re not the only cannabinoids, which you’re probably aware of. I’m talking about the well-beloved plant marijuana - or *cannabis*. I can’t count how many times I’ve been told: “cannabis is completely harmless!”. While I agree that there are drugs much worse than cannabis, I can’t agree that it’s *completely* harmless for *everyone*. It affects the endocannabinoid system and you shouldn’t trust anything that influences a system that controls *so many things* in your body. Want an example? There have been studies that suggest that cannabis might have a negative influence on male fertility. ![](https://cdn.pixabay.com/photo/2014/04/17/05/25/sperium-326157_960_720.jpg) Sperm production and maturation are influenced by the endocannabinoid system, which means excessive use of cannabis can lead to damaged or just generally very weak sperm. And while low doses of cannabis might increase libido, higher doses are associated with a total loss of it and even erectile dysfunctions. One study found a link between marijuana and lower testosterone, but a different study didn’t. Some studies suggest a link between the use of cannabis and more breast tissue in males (“man boobs”). None of this is certain, but it should be enough to be careful. But what else does cannabis do? Why does it feel so great? Why are people taking it? ![](https://cdn.pixabay.com/photo/2017/08/28/19/11/marijuana-2690984_960_720.jpg) Like most drugs, cannabis increases the amount of dopamine released in your body while you’re consuming it. As dopamine is part of your “reward and pleasure” system, it makes you feel good. But it also affects higher cognitive functions, learning, eating habits and other important bodily processes. And when you stop consuming cannabis, your dopamine level drops - but not to normal levels. Significantly lower dopamine levels were found in those who use cannabis a lot, which has negative effects on everything I just named. That can lead to memory and concentration problems, just as to more impulsive behavior. Additionally, a case study with a 38-year-old patient suggested that cannabis can cause psychotic states similar to schizophrenia in vulnerable people. Do you *know* how vulnerable you are to cannabinoids? I don’t. The amount of THC in marijuana has been increasing a lot. In 1972, it was about 1%, 3 - 4% in 1990 and in 2010 it reached almost 13%! Because of this, you can’t compare a joint today with a joint 40 years ago - and it’s almost impossible to predict the effects. But what conclusion should we draw from this? The human body is a complex and delicate system, especially when it comes to drugs. There is great potential for medical applications although we have to be careful, as there can be many side effects. If you’re using marijuana or are planning to use it, you should always be reasonable. You can’t know how your body will react. You might one day accidentally consume a higher dosage than before and be left with psychological issues. You could harm your body in a way that can’t be reversed. Or nothing might happen, and you’ll just have a good time. I hope this post wasn’t too dry for you, there was a lot of good information I wanted to share - you can see how much I read by checking my sources. I’m here for your questions in the comments! ![](https://cdn.pixabay.com/photo/2017/05/24/22/57/ask-2341784_960_720.jpg) --- ##### Sources: [Endocannabinoids and the Cardiovascular System in Health and Disease]( https://www.ncbi.nlm.nih.gov/pubmed/26408169) [The role of the endocannabinoid system in pain]( https://www.ncbi.nlm.nih.gov/pubmed/25846617) [The Endocannabinoid System and its Modulation by Phytocannabinoids]( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4604172/) [Marijuana, phytocannabinoids, the endocannabinoid system, and male fertility]( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651943/) [Endocannabinoid system]( https://en.wikipedia.org/wiki/Endocannabinoid_system#Basic_overview) [Marijuana: Effects of Weed on Brain and Body]( https://www.livescience.com/24558-marijuana-effects.html) [Cannabis induced dopamine release: an in-vivo SPECT study]( http://www.sciencedirect.com/science/article/pii/S0925492701001044) [Heavy cannabis use associated with reduced dopamine release in brain]( https://www.eurekalert.org/pub_releases/2016-04/cumc-hcu041416.php) [A Brain on Cannabinoids: The Role of Dopamine Release in Reward Seeking]( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3405830/) [The Effects of Dopamine on the Brain]( https://www.livestrong.com/article/418970-the-effects-of-dopamine-on-the-brain/) --- *Pictures taken from pixabay.com* --- Today I started mentoring @melanie00 for a week! We’re working on her science posts, so it’d be great if you’d drop by at her profile during that time (and after it too) 😊 --- *Got a scientific topic which you want to see as a story? Leave me a comment!* *You want to support scientists on Steemit? You **are** a scientist on Steemit? Join the #steemSTEM channel on steemit.chat and connect with us!* *STEM is an acronym for **S**cience, **T**echnology, **E**ngineering and **M**ath* ![SteemStem](https://steemitimages.com/0x0/https://steemitimages.com/DQmbm45GoXkP4CUEPgB7VA1YyfRXgs2RXYKSRvsQu6WT2i7/test1.gif) _{Monster GIF was made for me by @saywha and @atopy}