Hello mady
I have moved your post from the thread it was on in Introductions to start a new thread. It is better to start new threads for new topics. They will attract people's attention and also it is easier for reference
Judging from this forum, DHEA isn't used much at all. Some previous threads about it can be found here
http://www.thelupussite.com/forum/search.php?searchid=109850
If you google ( DHEA) you will find comments about it from Dubois including reasons why it isn't used much. Such as inconsistency of results and uncertainty of possible side effects and lack of knowledge about how it works. Most doctors regard it as an adjunctive at best, although it there is some evidence that it can improve general wellbeing and maybe some benefits for osteoporosis and cholesterol.
A synthetic version, Prestara, has been developed by Genelabs but hasn't so far got FDA appproval.
I have no idea about hormonal testing before taking it or during.
It is highly inadvisable to self treat or buy from a health store because the OTC brands are notoriously unreliable and like any medicine should be taken with medical supervision. The prescription 'sort' is to obtain a reliable product from a compounding pharmacy.
It is not available in the UK.

Clare