Trade Names: IGF1 LR3
Chemical Names: LONG™R3 IGF-I
Routes: Intramuscular or subcutaneous Injection
IGF1 is a growth promoting peptide that plays a critical role in our growth and development. It mediates most of the actions of HGH, one of which is skeletal muscle growth and does this by triggering new cell growth, and by stimulating the uptake of nutrients into growing tissues. IGF1 is produced in our bodies when HGH binds to growth hormone receptors in the liver and other tissues. When the liver releases IGF-1 it signals the body to begin to grow. The amount of IGF-1 produced is regulated by insulin, due to insulin’s ability to increase growth hormone receptor expression.
IGF1 LR3 is a synthetic 83 amino acid peptide hormone and IGF1 analog, with one amino acid substitution and an additional peptide chain added to the IGF1 sequence to increase biological activity and potency. This increases the half-life to 20-30 hours. It is significantly more potent than endogenous IGF-1 due to LR3’s reduced affinity for IGF1 binding proteins which render it biologically inactive. These binding proteins regulate interaction between IGF1 and IGF1 receptors, with over 90% of endogenous IGF1 being bound when it enters muscle cells.
IGF1 is structurally similar to insulin, and both hormones can bind to and activate each other’s receptors, but they do so typically in high concentrations. IGF1 LR3, like insulin, initiates the transport of glucose, amino acids, and electrolytes into muscle cells. This improved nutrient uptake is often experienced by the user as a ‘pump’ or muscle fullness that can last for hours. In clinical trials the most commonly reported side effect of IGF1 is hypoglycaemia, and this is to be expected from IGF1 LR3 as well. Thankfully nowhere near as severe as insulin related hypoglycaemia, which can be deadly.
Due to it’s long half-life most of it’s effects on growth are systemic - rather than local growth at the site of injection, as it will keep circulating the body until it finds a receptor to bind to. To maximize local growth the most widely accepted method is to inject IGF1 LR3 post workout bilaterally into the muscles that were worked. Heavy weight training upregulates IGF1 receptors in the trained muscle group, with IGF1 receptor activity being the highest 2 hours post workout. When IGF1 LR3 binds to receptors in skeletal muscle it stimulates protein synthesis, inhibits protein breakdown and begins the process of new growth and repairing injured tissue. It’s positive effect on carbohydrate metabolism, nutrient uptake and insulin sensitivity usually results in a significant reduction in body fat.
During resistance training the IGF1 gene is locally activated to produce an isoform of IGF1 called Mechano growth factor (MGF). MGF kick starts hypertrophy and repair of local muscle damage by activating and replenishing the pool of muscle stem cells called myoblasts. The nuclei required for new growth and repairing injured muscle cells comes from these precursor cells. When IGF1 LR3 is injected locally it binds to receptors on the myoblasts to activate the process of them becoming new mature muscle cells. The remaining IGF1 LR3 will go systemic and stimulate growth in whatever tissue has a high concentration of IGF1 receptors. It is therefore best to use the minimum dose required to produce results rather than risk unwanted organ growth.
100mcg injected post workout (split bilaterally) is the highest recommended safe dosage for advanced users, with many people reporting good results at 25mcg-50mcg a day. Results tend to taper off after 4 to 5 weeks on LR3, so it is best to cycle it one month on - one month off at 200-400mcg/week.
IGF1 LR3 is an extremely fragile peptide, and should be handled with care. It can easily be destroyed by improper storage or handling. It is usually supplied in either 100mcg or 1mg peptide vials, containing freeze dried powder that needs to be reconstituted. When reconstituted with 0.6% acetic acid solution it has a maximum shelf life of 2 years. If using bacteriostatic water it has a 30 day shelf life, or 24-48 hours with 0.9% NaCl sterile water. When reconstituting add the water very slow to the vial and do not shake it. The solution should be stored in the fridge at 2-4°C.