Drugs are very dangerous for your body for many reasons. One reason is because they are very addictive. Here, lets take marijuana as an example:
Well actually you are in luck I might have written your whole essay for you because I have this class in my school called Fit for life and they make us watch how drugs are bad and I took notes on the video. I got all the information from "National Geographic-Effects of Marijuana". And this is my own picture and handwriting. :)