The Institute of Human Anatomy has compared alcohol and cannabis, explaining how each substance moves through the body and affects long term health. Alcohol is water soluble, so it spreads rapidly through the bloodstream, passing through the stomach and small intestine before reaching the brain and organs. Over time, frequent drinking can damage the liver, increase cancer risk, and slow brain activity. In higher doses it can also disrupt memory formation, leading to blackouts where a person may appear conscious but later cannot recall events. Cannabis, particularly THC, behaves differently because it is fat soluble and can remain stored in fatty tissues, including the brain. Smoking delivers THC quickly into the bloodstream, while edibles pass through the liver first and produce longer lasting effects. Instead of causing direct organ damage in the same way as alcohol, cannabis mainly alters brain signaling, affecting perception, focus, and memory processing.

Alcohol and cannabis differ in broader risks and side effects. Alcohol is classified as a carcinogen and has a well established link to liver disease, heart problems, stroke, and several cancers, with no completely safe level of long term use. It can cause poor coordination, reduced judgment, and memory blackouts. Cannabis use is less likely to cause fatal overdose, but it can lead to anxiety, paranoia, increased heart rate, dry mouth, and difficulties with attention and learning. Heavy use may affect long term memory and motivation. Overall, research suggests alcohol causes more direct physical harm, while cannabis primarily changes cognition and brain function.