Both IGF-1 and human growth hormone (HGH) play a critical role in cellular growth and your overall health.
Insulin-Like Growth Factor-1 or, is a hormone that plays a vital role in helping children grow into strong healthy adults. It is remarkably similar to human growth hormone in that regard. Both HGH and IGF-1 are necessary for a child to meet growth milestones and achieve normal height.
HGH levels and your IGF-1 levels are intricately connected. HGH is produced by the pituitary gland. IGF-1 is produced by the liver, but it is the presence of HGH in the blood that tells the liver to make and release IGF-1.
IGF-1 is similar to HGH in that it helps bones and muscles to grow.
What Is the Difference Between HGH and IGF-1?
IGF-1 and HGH are intimately related. They serve some similar functions in the body, but they are not the same thing. They are both hormones, but different types of hormones. HGH is made by the pituitary gland, a gland of the endocrine system. IGF-1, like insulin is made, by a body organ, in this case the liver.
IGF-1 is made similar to the way insulin is made, and your body reacts to it the same way it does to insulin. This is why it is referred to as “insulin-like.” It is a “growth factor,” because it too, like HGH, stimulates cellular reproduction and the growth of tissue, particularly muscle and bone.
What Is the Function of IGF-1?
The primary function of IGF-1 is to help bone and muscle to grow. Beyond helping children to grow to their normal stature, IGF-1 is critical for optimal physical and mental performance in adults.
Once IGF-1 is released into your bloodstream by your liver, it stimulates cellular growth and regeneration, helping your body to recover and repair itself. Therefore, it is essential for keeping you strong and fit. It helps you to burn fat and build and maintain muscle throughout your life.
What Role Does IGF-1 Play in Growth Hormone Production?
HGH and IGF-1 are similar hormones that work in conjunction. HGH stimulates the liver to produce and release IGF-1. IGF-1 and HGH are what we call “synergistic.” That means that they rely on one another. Your production of IGF-1 depends on HGH, while the actions of IGF-1 enhance and promote the work of HGH, significantly increasing its ability to build muscle and stimulate cellular renewal.
IGF-1 and growth hormone work together, both playing a major role in the regulation of muscle mass and fat metabolism throughout the body.
How Are IGF-1 Levels Tested?
Your levels of HGH and IGF-1 vary depending on the time of day. They will also vary depending on your stress level, your weight, and your age. Your IGF-1 level is determined using a simple blood test.
IGF is measured in nanograms per milliliter (ng/mL). The normal ranges are:
- 182-780 ng/mL for people ages 16-24
- 114-492 ng/mL for people ages 25-39
- 90-360 ng/mL for people ages 40-54
- 71-290 ng/mL for people 55 and up
What Do My IGF-1 Test Results Mean?
If your levels are found to be below the normal ranges listed above, you may have a problem with low IGF-1. Low levels of IGF-1 can cause children not to grow properly. In adults, having below normal IGF-1 levels can increase your risk of developing a number of unhealthy conditions. Adults with low levels of IGF-1 are:
- More likely to have heart disease
- More likely to be obese
- More likely to have diabetes
- Are at a greater risk for Alzheimer’s dementia and other cognitive issues
- Are at a greater risk of osteoporosis
Generally speaking, adults with below normal IGF-1 levels will also experience:
- Weight gain
- Loss of stamina
- Loss of sharpness and mental acuity
Does Low IGF-1 Cause Low HGH?
Low IGF-1 does not necessarily cause low HGH, but they do go hand-in-hand. By its very nature, growth hormone stimulates the liver to produce and release IGF-1. Therefore, it is unlikely that you would have low IGF-1 levels, and not have low HGH levels as well.
How Are Low IGF-1 Levels Treated?
IGF-1 deficiencies are treated with IGF-1 injections. IGF-1 injections are given intramuscularly. Since it is likely that you will also have a growth hormone deficiency (GHD) if you have low IGF-1, you may also be prescribed HGH injections.
Because of their known synergistic effects, HGH injections and IGF-1 injections are often prescribed together. Since HGH stimulates the production of IGF-1, in some cases, growth hormone therapy alone, is enough to raise both your IGF-1 levels and HGH levels to where they should be.
Depending on your medical history, your test results, and lifestyle, your doctor will prescribe the best course of treatment for you to reach your health and wellness goals.
IGF-1 deficiencies are treatable with hormone replacement therapies.
Now that you know a little bit more about the relationship between IGF-1 and HGH, why not contact us today, and find out if you are a candidate for either one, or both of these life-changing therapies.
- The Gerontologycal Society of America
- Dr. Fuhman
- The relative roles of growth hormone and IGF-1 in controlling insulin sensitivity
David R. Clemmons J Clin Invest. 2004 Jan 1; 113(1): 25–27.
- Yakar S, Rosen CJ, Beamer WG, Ackert-Bicknell CL, Wu Y, Liu JL, Ooi GT, Setser J, Frystyk J, Boisclair YR, LeRoith D (2002). “Circulating levels of IGF-1 directly regulate bone growth and density”. Journal of Clinical Investigation. 110 (6): 771–781
- Levine ME, Suarez JA, Brandhorst S, Balasubramanian P, Cheng CW, Madia F, Fontana L, Mirisola MG, Guevara-Aguirre J, Wan J, Passarino G, Kennedy BK, Wei M, Cohen P, Crimmins EM, Longo VD (2002). “Low protein intake is associated with a major reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not older population”. Cell Metabolism. 19 (3): 407–417