I read that Avodart is for people with enlarged prostates and it helps to shrink them. However, what if I don't need to shrink my prostate? Will Avodart cause my prostate to shrink more than it needs to and is this dangerous?
Both Finasteride and Dutasteride are designed by nature to "shrink" (atrophy) the prostate. You cannot avoid this, as these drugs are specifically designed to target 5AR and inhibit DHT, which are found in abundance in the prostate (5AR2 especially).
Both drugs atrophy the prostate via cell apoptosis (death), which can lead to involution (progressive loss of function)... which can be of similar magnitude to castration.
Since Dutasteride inhibits up to ~99% of serum DHT via inhibition of Type I AND II 5AR, it is even more potent than Finasteride (only 65-70% serum DHT inhibition due to only inhibiting Type II 5AR). And since 5AR1 is found in the brain, you are taking an even bigger risk with Dutasteride by inhibiting 5AR1.