Detailed information about IGF-1 in bodybuilding applications


IGF-1 (insulin-like growth factor) is an endocrine hormone produced in the liver, and its production is increased in the presence of growth hormone. Many different types of cells in the body are equipped with receptors that accept IGF-1. This makes IGF-1 a good protagonist in the more autocrine cell signaling processes that target tissues to promote cell-cell communication (growth) or promote cell division. IGF-1 (insulin-like growth factor) is a growth factor that is closely related to insulin. It carries the same amount of amino acids as insulin and is responsible for the anabolic response to GH. IGF-1 is an important factor in children’s growth and is highly anabolic in adults. It is also known by the brand name Increlex and the generic name mecasermin.

Background of IGF-1

In the 1970s, IGF-1 was known as the “Sulfation Factor” and the “Nonsuppressible Insulin-like Activity” (NSILA). In the 1980s, it was called “Somatomedin C.” The most popular type of IGF-1 on the underground market is a more persistent version (longer amino acid length) called Long R3 Insulin-like Growth Factor-I or Long R3IGF-I. Lr3igf-1 is more potent than the smaller amino acid versions no longer available on the underground market. In this type of IGF, there are usually two types (Media and Receptor grades, respectively), with the last two types of IGFs primarily referring to the purity of the actual content in the bottle.

Mode of action of IGF-1

IGF-1 is released in the liver and binds to intracellular IGF receptors, ultimately leading to stimulation of cell growth (both causing new tissue formation and growth of existing tissue) and inhibition of cell death. It is a highly anabolic and anti-catabolic compound. This has many positive effects for bodybuilders: increased nitrogen retention and protein synthesis, as it possesses a high anabolic effect. IGF-1 (in the presence of sufficient protein) promotes the growth of new muscle cells, which increases the total number of cells in the muscle. IGF also has a protective effect on brain neurons and promotes the growth of new motor neurons, allowing them to learn new skills faster during use. IGF-1 is also responsible for connective tissue production, improving collagen formation, and contributing to cartilage repair. Likewise, it affects bone by helping with bone production and repair.

Benefits of IGF-1

Helps regulate the use of fat for energy, leading to fat loss. Helps with anti-aging. As we age, the production of IGF-1 slows down, leading to a decrease in cells. Low levels of IGF-1 are associated with heart failure, lower brain cell regulation, and neuronal function. Not to mention muscle tissue breakdown. Helps increase nutrient shuttle (protein synthesis). Increases regenerative function of neural tissues. Increases the ability of muscle cells to proliferate, resulting in fuller muscle tissue.

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Two different types of IGF-1

There are two types of IGF-1 variants: IGF-1 LR3 and DES IGF-1 (commonly known as IGF-1 DES). The common base IGF-1 has a very short half-life (about 10-20 minutes) and is metabolized by the body very quickly after use. This is why IGF-1 is modified to produce the amino acid analog IGF-1 LR3.


IGF-1 LR3 has a half-life of about 20-30 hours and is more potent than basal IGF-1. Since its half-life is approximately one day, IGF-1 LR3 will circulate in the body for approximately 24 hours, binding to receptors and activating cellular communication, thereby improving muscle growth and fat loss.

IGF-1 LR3 prevents glucose from entering the cells, thus forcing the body to burn fat instead of sucrose. In addition, because of the long half-life of IGF-1 LR3, there is no need for mandatory site-specific injections, as IGF-1 LR3 binds the body to all muscle cells for approximately one day.


DES IGF-1 is a shorter version of IGF-1. It is five times stronger than IGF-LR3 and ten times stronger than regular base IGF-1. IGF-1 DES has a half-life of about 20-30 minutes, so it should only be injected at the specific site where you want your muscle to grow. DES can stimulate muscle hyperplasia better than LR3. Simply put, it is best suited for spot growth rather than overall growth. In addition, IGF-1 DES is known to bind to lactate-deformed receptors during training. Lactate is normally present during muscle training, which allows IGF-1 DES to attach itself to mutated receptors and signal tissue growth during training.IGF-1 DES can be used longer and more frequently than IGF-1 LR3.

IGF-1 and HGH

HGH growth hormone is a precursor to IGF-1. Growth hormone does not directly cause muscle growth but indirectly causes muscle growth by emitting the release of IGF-1. Growth hormone (HGH) is usually very expensive and must be used with insulin or other anabolic steroids if significant muscle growth is to be induced.

Use of IGF

IGF-1 LR3: IGF-1 LR3 can be administered continuously seven days a week at a 50-150 mcg daily dose. Desensitization occurs at approximately 40 days or approximately four weeks. The injection site can be in any muscle group of the body, as it does not require forced spot injections. IGF-1 DES: IGF-1 DES can be given in multiple (pre-training) doses of 50-150mcg per day to specific target areas. Due to the short half-life of DES (20-30 minutes), desensitization is not noticed at all. The injection site should be spotted; injected into the muscle area where you want to promote growth. If you want to promote additional growth in your biceps, inject IGF-1 DES into your biceps.

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Side effects of IGF-1

High doses of IGF-1 can cause hypoglycemia, but not nearly as much as the effect of insulin on blood sugar. It is also noted and highly debated that IGF-1 has been shown to increase tumor size in cancer patients, but IGF-1 is not the cause of cancer; in fact, our bodies need IGF-1 to regulate heart function, the nervous system, and brain cell stimulation. People with low IGF-1 levels are often protein deficient, underweight, and thin, which is unhealthy.

IGF-1-related research data

In studies conducted on young adult mice, the compound responsible for increasing IGF-1 secretion in muscle fibers was given. Muscle mass increased by an average of 15% and strength by 14%. When the study was conducted on adult mice, the strength of the injected muscles increased by 27% compared to the uninjected muscles. It was also found to prevent muscle aging. Muscle mass and muscle fiber growth were similar to the levels seen in young adults. These effects are most likely due to the ability of IGF-1 to activate satellite cells and therefore stimulate muscle regeneration.

In studies conducted where GH and IGF1 were used together, an increase in lean body mass and fat loss was found over the use of each compound alone (2). The study also concluded that the use of testosterone also increased IGF levels in muscles. In a 12-week study using IGF-1, IGF-1+ GH, or GH alone subjects in this study, approximately 3kgs of lean body mass was gained, and approximately 2kgs of fat was lost. Intact human IGF-1 long R3 IGF-1 is 2-3 times more potent than IGF-1 because of the lower activity of the IGF-binding protein.

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