5-AD
I'd stay away from 5-AD from what I've read:
Patrick Arnold had this to say (although it was back in 1998) when he was discussing all the different prohormones at the time:
Compounds and Percent Testosterone Formed*
DHEA: 0.35%
5-Androstenediol: 0.19%
Androstenedione: 5.61%
4-Androstenediol: 15.76%
...and
"Another downside to 5-AD is its estrogenic activity. Numerous studies have confirmed that, at physiological levels, 5-AD acts as an estrogen agonist.7,8,9,10 In fact, in light of its dual activity as a mild androgen and estrogen, the accepted scientific name for this compound is now "hermaphrodiol" (from the Latin term meaning "of both sexes"). "
..and
"I'm not saying that taking 5-AD will have you in a training bra; in fact, when taken in moderate dosages, most people probably won't notice its estrogenic action. However, I do know one unfortunate person (myself) who experimented with 5-AD at large dosages (1-2 grams a day). This same unfortunate person was trying to fight off a lingering viral infection by taking advantage of 5-AD's immunostimulating action. As a result, this person ended up with a definite, and quite uncomfortable, swelling and tenderness in both nipples."
..in summary:
5-AD
• Testosterone Conversion: Low
• DHT Metabolite Conversion: No
• Estrogen Conversion or Estrogen Agonist: Yes
• Anabolic Properties: High
I don't want to misquote or take things out of context so you can read the whole article here:
http://www.testosterone.net/html/27proho.html