Testicle shrinkage is normal when taking a steroid. Over time your HPTA is suppressed and your body shuts down its natural production of testosterone. As a result the nuts shrink. When you stop taking the steroid, you need to go on a post cycle therapy (PCT) where you will use a SERM (Clomid, Nolva, or Torem) along with a Natural test booster like HCGenerate. The combination of these things will bring you back to normal over time usually....but there are never any guarantees even with a great PCT.