Yes, it is true. Not to the extent where steroids will completely shut your testosterone production down, but there will deifinitely be a reduced production of GH after using it. First of all, you would be introducing exogeneous hormone into your body, thus signalling it to stop producing the hormone of its own. Secondly, HGH is usually taken for a very long time. On the other hand, Nutrobal will stimulate your natural GH production. Therefore, there is a whole different mechanism involved, being Nutrobal a much better alternative.