The Study of EndoGH and Prolonged Stimulation of Endogenous Growth Hormone (GH) and Insulin-Like Growth Factor (IGF)

The Study of EndoGH and Prolonged Stimulation of Endogenous Growth Hormone (GH) and Insulin-Like Growth Factor (IGF)



The objective of this study was to examine the pharmacokinetic profile, pharmacodynamic effects, and safety of EndoGH, which is composed of GH analogues in releasing protein and fragments of GH, to enable the safe release of 191aa GH located in the pituitary gland of the human body. This delivery will enable endogenous GH in such that 97% of GH is bound to binding proteins for further processing without any substantial surplus of mitogens in serum.


The study was a randomized, dose trial with durations of 15 and 30 days. GH readings were done at baseline, 15d and 30d intervals.

The study was performed at various investigational sites. Laboratory results utilized Human Growth Hormone (hGH) Double Antibody RIA Kit from MP Biomedical.

Healthy subjects, ages 25–65 yr, were studied (female & male).

EndoGH was administered by the user in doses of 2-3IU daily based on the weight of the individual.

The main outcome measures were peak concentrations and area under the curve of GH and IGF-I obtained from lab results.


IGF-1 Serum Level

After a single administration of EndoGH, there was dose-dependent increase in mean plasma GH concentrations by 2- to 20-fold during a 1min to 30min period, also in mean plasma IGF-I concentrations by 0.2- to 0.3 fold for 15-30 days. The estimated half-life of EndoGH was 2hrs. After 60 doses of EndoGH, mean IGF-I levels remained at or above baseline for up to 30 days. No serious adverse reactions were reported. IGF-1 levels remained as a safe concentration in serum. Weight loss, increased skeletal muscle and neurogenesis were all noted as an outcome of this study. Unlike traditional GH, virtually no water weight or abdominal distention was demonstrated in the entire cohort.

Levels of IGF-1

Traditionally IGF-1 has been used as an index of IGF bioavailability in the human circulation, but this fails to demonstrate the IGF-1 binding to other IGF Binding Proteins, and the fact that IGF-2, is more abundant than IGF-1 in the bloodstream and resides in the majority of binding sites of IGFBP-3. This inaccurate reading can lead to plethora of problems, such as abdominal distention. IGFBP-3 can bind to IGF-1 & IGF-2 which is remitted by many cells and can very well block their access to the IGF-1 receptor (IGF1R), which is activated by both IGF types 1 & 2. Thus, IGF-1 should be kept in a normal range of 100-300 ng/mL.


Administration of EndoGH resulted in sustained, dose-dependent increases of GH and IGF-I levels in healthy adults and was safe and well tolerated, particularly at high doses of 20IU. There was evidence of a cumulative effect after multiple doses. These data support the utility of EndoGH as a therapeutic agent to increase endogenous GH to optimal levels safely.

History of Growth Hormone

Human Growth Hormone is an endocrine hormone that is produced by the anterior portion of the pituitary gland. It is made up of 191 amino acids. The production of GH significantly decreases as adults age. The entire human body is dependent on HGH for proper functioning. It can provide necessary fulfillment benefits both in children as well as in adults where normal physical growth has been deficient. Children with stinted growth due to lack of naturally produced growth hormone can benefit from GH while adults suffering from the same deficiency either since childhood or resulting from hypothalamic disease, surgery, radian therapy or trauma would be good candidates for GH.

As adults age, our bodies' natural GH production decreases. The effects of aging are a result of this decreased production. Clinical evidence suggest that by

replacing Human Growth Hormone in IGF-1 deficient adults, can significantly eliminate the symptoms of aging, reverse the biological effects of aging, reduce body fat, increase lean muscle mass, reduce muscular atrophy, strengthen the heart and improve sexual performance.

Exogenous vs. Endogenous GH

In patients with intact pituitary function, there has been interest in the use of endogenous GH releasing proteins rather than exogenous GH in the hope of producing a safe physiological pattern of tissue exposure to GH than occurs by a single daily injection of the exogenous GH. Exogenous GH administration in humans attenuates the endogenous GH response to stimuli causing some of the side affects normally associated with exogenous GH use. These side effects include acromegaly (the enlargement of fingers, bones, organs). Administration of endogenous GH will not cause any of the negative side effects of exogenous GH since the action of mechanism relies on a body’s capability of releasing GH. Analogous to this, whether we are 90 or 30 years old, our body is capable of producing pure, 100% absorbable, safe endogenous GH with no side effects since there is no excess GH available that normally is left by exogenous GH use. In fact, several studies in both children and adults have suggested that comparable results can be achieved with GH releasing protein therapy.

Molecular Structure

GH releasing protein fragments composed of the 191aa chain enhances the tertiary structure of the protein, increases efficacy, prevents degradation, and sustained bioactivity. This binding extends the half-life of the active pharmacophore, resulting in a markedly prolonged duration of action. Moreover, past studies indicate that physiological GH secretion is maintained, and IGF-I levels are enhanced for several days after a single application.


We assessed the safety, tolerability, pharmacokinetic profile, and effect of EndoGH on circulating concentrations of GH and IGF-I in a randomized study in healthy adult subjects. Subjects consisted of healthy men and women, ages 25– 65 years, with a body mass index of 30 kg/m2 or less and IGF-I levels in the normal range for age and gender.

GH & IGF Serum

Serum GH was measured by catalog# 07151102 MP BIOMEDICALS Human Growth Hormone (hGH) Double Antibody RIA KitIGF-I.
Serum IGF-I was measured by IGF ELISA kit.


Serum GH concentrations
Pre-dermal application of GH concentrations ranged from 1.1–1.8 ng/ml. Application dosing was carried out in 4-to 8-pump daily doses (2.6 IU to 5.3 IU)

Mean GH concentrations increased by 2- to 4-fold after a single-application of EndoGH as described in Fig 1. This suggests a sustained pulsatile GH secretion.


The median peak GH level occurred within 1 h in all groups. 

Serum IGF-I concentrations

Pre-injection application of IGF-I concentrations ranged from 80–170 ng/ml. IGF-I levels remained elevated compared with baseline for 15 days after a 30 day application of EndoGH in all dosing groups and mean levels increased by 0.5- to 1.7-fold over baseline (Fig. 2). 

Other Measured Hormones

GH Serum Level

There were no significant increases in serum cortisol, prolactin, TSH, or LH levels after a 30 day EndoGH study.


In the bolus single-dose study (10IU), no adverse events were reported in subjects. In the 30 day study, no local reaction from allergies associated with EndoGH occurred. The EndoGH was considered well tolerated.


This report describes the safety, pharmacokinetic profile, and pharmacodynamic effects of EndoGH, a secretagogue, of the 191aa GH that is absorbed and covalently binds to serum albumin after pulse. In addition, there was clear evidence of a dose-responsive and sustained biological effect, with elevated GH and IGF-I & IGF-2 serum concentrations persisting for at least 15 days, after the 30 day study. EndoGH is considered safe and generally well tolerated, particularly at high doses of 10 to 20 IU.

Treatment with human GH typically consists of a single daily injection of the hormone, resulting in transient supraphysiological levels, followed by a decline to baseline. However, failure to mimic the physiological pulsatile nature of GH secretion may preclude optimal therapeutic effects and may contribute to some of the adverse effects that have been observed even in the presence of normal serum IGF-I levels. This can be compared to the use of exogenous testosterone and the shut down of the Hypothalamus Pituitary Testicular Axis (HPTA). In contrast, applications of EndoGH, stimulate the pulsatile release of GH and renders practical for therapeutic use. Therefore, the availability of a endogenous GH with a sustained effect has important therapeutic potential.

In summary, administration of EndoGH resulted in a 2- to 20-fold increase in mean serum GH levels in all dosing groups and a dose-related increase in mean serum IGF-I levels was observed, ranging from 0.2- to 0.3-fold and persisting for up to 15 days after a 30 day application. Additionally, a single application of EndoGH produced sustained elevations of serum GH and IGF-2 levels in normal subjects for nearly 18 hrs.

April 23, 2017 by Richard Rodriguez
Tags: EndoGH GH IGF1

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