Growth Hormone 101: Understanding the Basics and Challenges

In this video, the speaker provides an overview of growth hormone (GH). GH is responsible for determining height and plays a significant role in the proper development of bones and connective tissue during puberty. However, its importance decreases in adulthood. The speaker discusses the challenges of measuring GH, as it is pulsatile and difficult to assess accurately. Instead, the levels of insulin-like growth factor 1 (IGF-1) are commonly used as a proxy for GH production. The speaker also talks about the relationship between GH and IGF-1, their impact on lipolysis and fat storage, and the intricate feedback loop involved in their regulation. The video ends with speculation about the flexibility of the pituitary gland to restore its GH production after exogenous GH use. Anecdotal evidence suggests that GH may aid in tissue rehabilitation during periods of healing, such as burn victims or orthopedic injuries, but more research is needed.

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Key Insights:

  • Growth hormone (GH) is the primary hormone responsible for determining height during growth and adolescence.
  • GH is important for proper development of bone and connective tissue during puberty.
  • GH levels drop significantly as you reach adulthood and decline even further as you age.
  • There is ongoing debate about whether GH replacement therapy is beneficial for optimizing function, fat loss, and vitality.
  • GH is often framed as a „Fountain of Youth“ elixir, but claims should be scrutinized due to financial incentives of proponents.
  • GH is responsible for the growth of broad-spectrum tissues during growth and regulates lipolytic action.
  • GH production is regulated by various factors, such as fasting, sleep, and calorie deprivation, and its actions involve the liberation of free fatty acids for energy.
  • Igf-1 is the best proxy for GH production and is widely accepted as a biomarker for assessing GH levels.
  • GH and igf-1 have complex interactions, with GH promoting lipolysis and igf-1 promoting fat storage, creating a balance between anabolic and anti-catabolic processes.
  • GH replacement therapy can lead to suppressed endogenous GH production, with igf-1 elevations being an indicator of exogenous GH use.
  • GH and igf-1 levels can be used to adjust the dose of GH replacement therapy, targeting optimal function based on reference ranges.
  • GH is regulated by a feedback loop involving gin receptor agonism, ghr receptor activation, and somatostatin release.
  • Pituitary flexibility allows endogenous GH production to bounce back relatively quickly after stopping exogenous GH use.
  • GH has been used in medical settings for tissue restoration in burn victims and may potentially aid in rehabilitation during orthopedic injuries.
  • Anecdotal evidence suggests the effectiveness of GH in rehabilitation, but there is a lack of controlled studies.


Let’s have a Growth Hormone 101. Growth hormone is known as the primary hormone responsible for determining height during adolescence. It plays a significant role in the proper development of bones, connective tissues, and overall growth. However, as you reach adulthood, the production of growth hormone decreases significantly and continues to decline with age.

The question arises whether replacing growth hormone can optimize functions such as fat loss and vitality. This is where things can get tricky. Many proponents of growth hormone replacement have a financial incentive, making it difficult to separate fact from fiction. Growth hormone is often touted as a Fountain of Youth, with claims of preventing age-related declines in bone strength, fat burning, and overall function.

At a broad perspective, growth hormone is responsible for tissue growth during both childhood and adolescence. However, in adulthood, it becomes less relevant for height and more involved in regulating lipolysis, the process of releasing free fatty acids into circulation. It acts as an opposing hormone to insulin, promoting the utilization of fatty acids as an energy source.

Measuring growth hormone can be challenging due to its pulsatile nature. Even injecting a large dose of growth hormone only results in a transient spike in serum levels. Therefore, the most widely accepted proxy for growth hormone production is insulin-like growth factor 1 (IGF-1). IGF-1 is produced in the liver and has implications for tissue growth and maintenance, especially in muscles.

The relationship between growth hormone (GH) and IGF-1 is complex. GH stimulates the production of IGF-1, which is involved in anabolic processes, including fat storage. GH, on the other hand, promotes lipolysis and has anti-catabolic actions. The balance between these hormones is maintained through feedback loops, where the presence or absence of one hormone influences the production of the other.

When administering growth hormone, the dose is often determined based on a person’s IGF-1 levels. However, this can be influenced by various factors, such as liver function and individual responses to different situations like fasting or calorie deprivation. It is important to consider these factors when determining the appropriate dose.

As for measuring endogenous GH production, it can be shut down when exogenous growth hormone is administered. Elevated IGF-1 levels trigger negative feedback, leading to a decrease in GH production. However, the pituitary gland, responsible for GH production, appears to maintain its flexibility and can resume production after the exogenous administration is halted.

In medical settings, GH may be used to aid in tissue restoration during healing periods, such as burn injuries. It plays a crucial role in reversing the catabolic state and promoting anabolic recovery. However, the evidence for using growth hormone in orthopedic injuries or rehabilitation periods is mainly anecdotal. There are limited studies and counterfactual data to support claims of its effectiveness.

In conclusion, growth hormone plays a vital role in growth and development, especially during adolescence. Its effects become less significant in adulthood, but it still contributes to various metabolic processes. Measuring GH directly is challenging, and IGF-1 is often used as a proxy. The use of growth hormone in rehabilitation and tissue restoration is anecdotal, lacking substantial evidence.