A decabol and testosterone cycle will suppress natural testosterone production. Any steroid will suppress natural testosterone production, whether it be an oral or an injectable. A proper PCT is essential to not only restore natural testosterone production but also to ensure you keep all the gains you made in the steroid cycle itself.
In this video I explain how to properly run a PCT after a steroid cycle ->
http://www.evolutionary.org/forums/anabolic-steroids-peds/video-how-run-proper-pct-46615.html
The perfect PCT article explains what dosages to use:
http://www.evolutionary.org/the-perfect-post-cycle-therapy-pct/
The perfect PCT is arguably the best PCT protocol you can run. It is comprised of the SERMS clomid and nolvadex, the AI aromasin, HCGenerate ES (a good natural testosterone booster), N2guard (a liver/organ detox supplement) and the SARMS ostarine and cardarine.
• Clomid and Nolvadex increase levels of LH and FSH in the body, which increase free testosterone levels.
• An aromatize inhibitor will prevent testosterone from aromatizing into estrogen and prevent side effects like gynocemastia and water retention.
• A natural testosterone booster (like HCGenerate ES) will signal the leydig cells in the testicles to restart testosterone production.
• A liver/organ detox supplement (like N2guard) will help cleanse the liver and kidney, regulate blood pressure and balance cholesterol levels.
• Ostarine will prevent muscle loss during a PCT when the body is catabolic from the increased cortisol levels and low anabolic hormones.
• Cardarine will prevent fat gain during a PCT protocol when hormones are low and cortisol levels are high.