Dear members,

I've been asked many times by customers about the notion that GH therapy requires the addition of T4 in order to potentiate the GH anabolic effect. This notion was brought to public by Mr Anthony Roberts who is/was considered an authority in the BB arena, and on 2006 recommended on the addition of T4 to any GH treatment

It really intrigues me how he Mr Roberts got the notion that T4 may support anabolism with GH

First on any clinical treatment by doctors, both for growth deficiency as well as in HRT, no T4 is added to the GH (unless there are low T4 levels as a results of thyroid functioning which required T4 therapy)

Below you may see a quote from a basic endocrine summary on GH-thyroid interaction -

"Administration of growth hormone (GH) in GH-deficient patients has been reported to cause a variety of perturbations in thyroid function. Reports range from decreased sensitivity of thyrotropin (TSH) to thyrotropin-releasing hormone (TRH) stimulation and induction of hypothyroidism to increased energy expenditure and enhanced peripheral thyroxine (T4) to triiodothyronine (T3) conversion"

• GH indeed may alter thyroid functioning, its generally not the case with a healthy athlete under average GH dosages, but always thyroid functioning should be in check. Adding exogenous T4 to the GH will only sabotage more the thyroid functioning, and certainly won't support the thyroid or prevent the phenomena of decreased TSH sensitivity.

• As you may see GH increases the body's metabolism by increasing T4 -> T3 conversion, this is one of the known metabolic effects of the GH as a fat burner, so adding T4 will simply increase the T3 level even higher (while suppressing endogenous T4 secretion). Too high T3 levels have a catabolic effect and are certainly not necessary, unless fat burning is a top priority. Too high T3 levels will impair also insulin and IGFs functioning.