Yes meth shrinks your dick, and yes the shrinking can become permanent from my understanding. The longer you're exposed to the drug the more likely the chances of the decrease in size becomming permanent, as your body will decide that it needs the blood flow in more "important" areas of the body. Your best bet is to kick the habit right now...besides, do you realize what is in meth? Why would you want to put those substances in your body? If you do meth, a small dick is the least of your worries... **steps down off of soap box**