Human Hormones

Insulin-like growth factors (IGFs) are hormones found in the human body. There are two types of IGFs found in the human body: IGF-1 and IGF-2. IGF-2 is found in fetuses and is responsible for growth and development, and development and function of a fetus’ brain, liver, and kidneys. IGF-2 is secreted by the brain, kidneys, pancreas, and muscle. There is currently no form of synthetic IGF-2.

IGF-1 is secreted by the liver in both children and adults. Its structure is similar to that of insulin. IGF-1 is classified as a peptide hormone.
Secretion and Production

IGF-1 is produced in and secreted from the liver. Its production is stimulated by somatotropin. The primary effect of IGF-1 is the promotion of cell growth and multiplication. Almost every cell in the body is affected by IGF-1, including muscle, cartilage, bone, liver, kidney, nerve, skin, and lung cells. Additionally, IGF-1 has insulin-like effects.
Pharmacological Uses

IGF-1 has been synthesized and has many of the same effects as synthetic somatotropin. However, because somatotropin causes the secretion of IGF-1, many of its effects are actually indirect as they are direct effects of IGF-1. Therefore, somatotropin is actually a precursor to IGF-1. The human body produces IGF-1 at its highest levels during puberty, with the level of secretion declining as a person ages. There are many common effects and uses of IGF-1, some of which are still being researched:

Laron Dwarfism
Laron dwarfism is a disease that causes growth deficiency due to a lack of production and secretion of IGF-1. Synthetic IGF-1 can be administered to patients to reverse this deficiency.

Amyotrophic Lateral Sclerosis
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that causes progressive muscle weakness and loss of motor neurons. Because IGF-1 can help to restore and protect muscle cells, it may be of benefit to patients with ALS. IGF-1 may slow the progression of weakness in persons with ALS.

Performance enhancing drug
IGF-1 is commonly used as a bodybuilding or physical and performance enhancement drug. There are many effects of IGF-1 supplementation that are of benefit to athletes. First, IGF-1 causes the body to grow new muscle cells, something that does not naturally occur after puberty. It raises a person’s metabolism, therefore allowing them to lose weight even during inactive periods. It causes formation of lean muscle, unlike steroids that cause a person to gain mostly water weight. IGF-1 strengthens joints and ligaments, heals damaged tissue, shortens recovery time between workouts, and enhances overall performance with less risk of detection than other performance-enhancing drugs. Because IGF-1 is natural hormone, side effects are rare and generally only occur when the drug is abused.

Weight Loss
Normally, a person’s body uses all of their glucose for energy before seeking that energy from their fat reserves. IGF-1 forces your body to seek energy from the fat reserves first. This results in significant weight loss. Additionally, IGF-1 raises metabolism and promotes the growth of lean muscle.

Anti-Aging
As a person ages, the amount of IGF-1 their body produces declines. This means that one’s body is less able to repair their damaged cells. Cell damage is what causes aging. IGF-1 is commonly used as an anti-aging drug to prevent and heal cell damage resulting in wrinkled skin, bone deterioration, and memory loss.

AIDS Wasting and Cachexia
IGF-1 is commonly used to treat AIDS wasting and cachexia. It works to build new muscle cells, increasing muscle density. Because your body can build new muscle cells, it is much easier to develop and maintain lean muscle.

Burns and Nerve Damage
Because IGF-1 works to heal damaged cells, it is often used to treat both burn victims and persons with nerve damage. IGF-1 can work to heal damaged skin cells and nerve cells, therefore expediting healing in burn victims and persons with nerve damage.