I'm taking Test C, 250MG EW and Deca, 300MG every EW. I've been on Test cyp for years on a doctor prescribed TRT. I added the Deca more for therapeutic reason abut 5 weeks ago. The past few weeks I have been so tired and non motivated. I hate this. My RBC's will be getting checked today. That may be the issue, but something is telling me it is the Deca causing this. Can Deca cause lethargy? It's pretty extreme.