Thread: WHY YOU NEED T4 WITH YOUR HGH

Originally Posted by Pharmaca

The notion of adding T4 to GH was introduced to the BB community by Bill Llewellyn. This idea in not only counter productive but actually harmful in most cases.

GH simply enhance the conversion of T4 to T3 (this is one of the main paths by which GH increases the metabolism), more T3 in the serum (which is the active form of T4) signals the thyroid to produce less TSH through a normal negative feedback (the body thrives to balance the metabolism so if it senses higher T3 levels this means that the metabolism is raised, so the pituitary gland secrets less TSH to balance this, and less TSH means less T4), this is all normal and healthy.

Adding exogenous T4 will do 2 things which are unwanted -

1. It'll increase further more the metabolism which is already higher under GH usage, this may lead to a catabolic effect

2. It'll suppress the thyroid gland and may lead to hypothyroidism

What is advised is like mentioned already to keep the thyroid function in check (as there is a higher tendency under GH usage to develop hypothyroidism), and only of the thyroid functioning is diagnosed as harmed there is a need to add exogenous T4

We're offering pharma grade GH, we encourage our customers to make blood tests to asses the clinical effects of the GH, and will offer credit to any member who posts serum test

This is the study that highlights the increase in T4 to T3 conversion after HGH administration: Error - Cookies Turned Off


The effect was pretty amazing. It brought Free T3 levels from the bottom of the range (around 2 pg/mL range) to the very top of the range (in the 4 pg/mL range). The study postulates that some of the positive effects of GH may be mediated through the increase in T3 levels. It can explain some of the positive effects on metabolism and skin health. The other positive health benefits are likely attributibal to IGF-1 AND the HGH itself independent of IGF-1 increases. (From other studies)


The participants were put in groups of 1, 2, and 4 IU of HGH. Most of them were already on Levothyroxine (T4) for hypothyroidism at an average dose 100-200 mcg daily. Very interesting data in here.


Here's the study unlocked if anyone wants to read up:

Sci-Hub | Growth hormone administration stimulates energy expenditure and extrathyroidal conversion of thyroxine to triiodothyronine in a dose-dependent manner and suppresses circadian thyrotrophin levels: studies in GH-deficient adults. Clinical Endocrinology, 41(5), 609–614 | 10.1111/j.1365-2265.1994.tb01826.x