This site will you a little about it.
Havoc is name of 2a,3a-epithio-17a-methyl-5a-androstan-17b-ol, made by company RPN
http://www.supplements.net/RPN-Havoc
Havoc's active ingredient, 2a,3a-epithio-17a-methyl-5a-androstan-17b-ol, is an analog of an aromatase inhibitor.
Ive heard results...