This is a true story!!
I had a bottle of deca that was 1.5 yrs over. I went ahead and used it and it gave my the worst gyno ever. I just had it removed!!
Seriously, I had done several cycles before that and never had a problem. I was only taking 300mgs/week and in like one week, my nips were on fire.
I have since done a new bottle and had no problems.
I would not touch the stuff. Depending on the bottle/type you have, a few bucks is not worth getting gyno. Just go buy a new one!
I have no idea if the expired deca was the cause but I will never take chances like that again!
just FYI