What is difference between mesterolone vs testosterone?

Lots of difference: mesterolone is an oral T. It and other oral Ts do not help much and may have some liver side effects. Testosterone Undeconate is the only oral product I know which is approved and safe. Not yet approved in USA. WHY???? DHEA is over the counter approved replacement for the adrenal source of T. It is OK and has been called the anti aging supplement. Gels or depo shots best way to replace T.