Water is responsive to microwave radiation due to the hydroxyl groups (remember: H-OH)...and all prohormones are also reactive for the same reason.
As a side note, esterfied species are more prone to structural integrity issues with microwave radiation.
It is never a good idea to microwave your gear.
What I was trying to get at above is instead of treating the symptoms I would rather attack the problem itself...which it seems in this case is the matrix that it is dissolved in. However, I don't have any other info such as concentration, matrix constitution, etc. which is vital to issue resolution.
How about a little more info?
Chemo