TweetHCG has a slight effect. It mainly mimics LH which is not directly responsible for sperm production. HMG mimics FSH which does. Now HCG and HMG therapy together have a synergistic effect. Even while on HRT it can bring levels to normal after years of suppression. I can not say for sure that deca will effect it, but if your main goal is procreation, then personally I would stay off of it.