I've read that testosterone (cyp,enth,prop) used solo for extended periods of time leads to a reduction in collagen synthesis. Is this fact? I've also read that Deca , Equipoise , or Anavar can be combined with test to improve collagen synthesis. Fact?

What would be the most effective (Deca, Equipoise, or Anavar) to add with cypionate or enanthate ? Is it Deca?