Pump the brakes before we get way off track here.

Ok so Androstane's

Androstane - Wikipedia, the free encyclopedia

Are the core of DHT based hormones without ketones or Hydroxy functions.

For all intensive purposes never worry about 5b androstanes, they don't do anything we are concerned with.

For the 2 step precursors to DHT we have

Androsterone which chemically has a 3 alpha hydroxy function and a 17 ketone function.

Epiandrosterone which chemically has a 3 beta hydroxy function and 17 ketone function. Also this is sometimes called Stano.

If you have a estered compound, the ester is always attached to where the hydroxy function is so in active steroids that are estered it would be in the 17th position, in these it has to be in the 3 position because that is where the hydroxy function lies.

As for effectiveness I believe in theory the Epiandrosterone should be more effective due to the body's natural ability to want to convert DHEA. In actual application results may vary.