Difference In DHT Types?

Just wondering what is the difference between type 1 and type 2 alpha reductase? If proprecia only inhibits type 2 alpha reductase what is it targeting besides scalp tissue? Can reducing it damage some other tissues in the body?

Dihydrotestosterone (DHT) is part of the metabolic pathway in the breakdown of testosterone. Wikipedia has a very good overview which will cover much of what you asked.

I am often asked why I do not recommend dutasteride for treating hair loss (aside from the fact that it isn’t FDA approved for that), and that is because it is both a 5-alpha reductase type 1 and a type 2 blocker, and its impact may produce more side effects than finasteride, which is strictly a type 2 blocker. I’ve read that dutasteride is 3 times more potent at blocking type 1 and it may be 100 times more potent at blocking type 2 than finasteride. There are many target organs that will be impacted when you take a DHT blocker, so it is always best when using a drug to get it down to its simplest and lowest possible dose to minimize the side effects that might be experienced. Fortunately, the 1mg dose of finasteride works for most people with significant side effects in less than 2% of the male population taking it.