It depends on the type of HGH therapy being taken. The HGH injections can shut down the pituitary gland's own release of growth hormone. Stopping HGH injection therapy abruptly may cause a rebound effect where the benefits previously gained are lost because the pituitary gland has become accustomed to not releasing growth hormone and so the level can drop below what it was before the therapy was started. Injectable HGH should be cycled in order to try to prevent the pituitary gland from becoming lazy and thereby lessening the rebound effects.
HGH in homeopathic form will not decrease the pituitary gland's own release of growth hormone but should help to improve its release.