IGF-1 LR3 (1mg)


Size: 1mg
Contents: IGF-1 LR3 (1mg)
Form: Lyophilized powder
Purity: >99%

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IGF-1 LR3 for sale

IGF-1 LR3 peptide, a polypeptide amino acid also known as Long arginine 3 IGF-1, or LR3-IGF-1, has been shown in various research studies to have the potential benefit to burn fat, through increased lipolysis, aiding in weight loss, and to build muscle by promoting protein synthesis and muscle recovery.

Complete Guide to IGF-1 LR3

Growth hormones play a vital role in overall development and growth of the body. It also helps in elevating protein production, fat metabolism, and governing the key body systems such as cardiovascular and nervous system. Furthermore, it also elevates the levels of IGF-1 in the body (1).

Insulin-like Growth factor-1, or IGF-1, is a naturally produced protein that is composed of 70 amino acids. Structurally similar to insulin, this protein mainly regulates cell tissue and body growth and development.

There are two synthetic variations of IGF-1; firstly, the synthetic IGF-1, which is identical to the natural protein and stimulates similar effects as IGF-1; and second, is IGF-1 LR3, which is also synthetic in nature, but is more potent than the natural protein.

What is IGF-1 LR3 peptide?

IGF-1 LR3 is a synthetic variant of the naturally occurring IGF-1, which contains an extended N-terminal structure and arginine acid at residue 3. Hence, it is named IGF-1 Long R3 (2).

Owing to the altered structure, IGF-1 LR3 binds poorly with the type 1 IGF-1 receptors and hence the blood plasma concentration of the IGF binding proteins remains increased. This results in a much higher potency of IGF-1 LR3 compared to the natural or synthetic IGF-1 (2).


During the years 1940 to 1950, a growth hormone somatotropin was discovered where it was found that it led to an increase in the sulfate uptake in normal, healthy rat serum. This ‘sulfate factor’ was isolated from the rat serum and named ‘somatomedin.’ On the other hand, another independent study was ongoing to examine the components producing insulin-like activity. During this study, it was determined that these components were in fact the ‘somatomedins’ and were then finally named as insulin-like growth factors.

Further mutations of the insulin-like growth factors were carried out using gene targeting approaches to increase its bioavailability and potency.

During these mutation studies, IGF-1 LR3 was synthesized with an additional arginine acid and an extended structure at the N-terminal, producing a protein composed of 80+ amino acids, as opposed to 70 amino acids found in natural IGF-1 (3).

Working mechanism of IGF-1 LR3

IGF proteins mainly exert their effects by binding with the IGF-1 receptors (hence called the IGF binding proteins). However, studies have shown that these IGF binding proteins, including IGF-1 LR3 can function either via IGF receptor dependent mechanism or via IGF independent mechanisms (3,4).

A study (3) was conducted where an experimental mouse body was created substituting the endogenous IGF-1 with IGF-1 LR3.

During this study, it was determined that upon injecting the IGF-1 LR3 into this model, the synthetic protein was quickly cleared from the serum and distributed into the body tissues. At the end of the study, these experimental mice showed elevated growth and more strong, robust bones in comparison to the controls. The controls were the normal, healthy mice with the natural IGF-1 proteins.

These results demonstrated that IGF-1 LR3 was more potent than IGF-1 regardless of the rapid serum clearance. This was because IGF-1 LR3 has a poor binding affinity towards the IGF-1 receptors. Consequently, the concentration of IGF-1 LR3 remains elevated in the plasma and can easily get distributed amongst the tissues.

Also, it suggests that IGF-1 LR3 stimulates a signaling mechanism in the body, either via autocrine mode (where the tissue cell stimulates itself) or via paracrine mode (where the tissue cell stimulates the nearby cell). The increased bioavailability of these autocrine and paracrine IGF-1 LR3 proteins play a vital role in producing its effects.


The main advantages of the IGF-1 LR3 peptide include:

  • Treatment of growth hormone IGF-1 deficiency
  • Elevated lean muscle mass
  • Decrease body fat
  • Increased metabolism
  • Improved recovery rate
  • Increased bone density
  • Potential treatment of muscle dystrophy
  • Potential treatment of diabetes

Research and Clinical studies

IGF-1 deficiency

While there is sufficient data online to affirm that IGF-1, and thereby IGF-1 LR3, is approved for use in patients suffering from IGF-1 deficiency (5), there are few completed clinical studies available for IGF-1 LR3 study.

There is a 2005 study (6) where the effects of rhIGF-1 on patients suffering from IGF-1 deficiency and growth disorders were studied. This study can be referenced here in lieu of IGF-1 LR3, considering these two compounds are similar to IGF-1.

RhIGF-1, also called Mecasermin, is the recombinant form of insulin-like growth factor 1, and has successfully been used in the treatment of GH insensitivity for over 20 years since its discovery. RhIGF-1 is a synthetic form of IGF-1 that is exogenously administered to overcome the GH deficiency (11).

45 participants with natural short stature were enrolled in this controlled study, where rhIGF-1 was administered at a dose of 60 mcg/kg once daily to all the participants via subcutaneous route. The doses were then adjusted at the later half of the study based on the participant’s age and gender, up to a maximum given dose of 240 mcg/kg per day.

The heights of all participants were measured before and after the study. It was noticed that there was an average increase in height by 7cm per year in all participants treated with rhIGF-1. Hence, this study demonstrates that IGF-1 analogs have a positive effect in treating growth deficiency. The same can potentially be said for IGF-1 LR3, making it a potential agent to be used in the growth hormone deficiency in humans.

Fat metabolism and diabetes

Studies (7) have demonstrated that IGF binding proteins, including IGF-1 LR3, induce glucose uptake and thereby glucose metabolism through the activation of signaling mechanisms. Since peptides like IGF-1 LR3, which have poor binding abilities toward IGF-1 receptors, exerted similar effects of glucose metabolism, it was understood that these effects are independent of the protein binding to IGF-1 receptors.

As a result of the glucose uptake, IGF-1 LR3 causes an overall decrease in the blood sugar levels. This decrease in sugar levels then stimulates the adipose tissue and liver to conduct lysis (breakdown) of glycogen and triglycerides, thus resulting in fat metabolism.

Thus, the peptide elevates fat metabolism and decreases body fat and demonstrates a promising effect with the potential to be used as a therapeutic agent to treat diabetes.

IGF-1 LR3 and Muscle Dystrophy

This study (8) was conducted on female mice to examine the effects of IGF-1 LR3 on reducing the effects of myostatin.

Myostatin is a muscle protein that primarily prevents muscle cell differentiation and growth. Reducing the effects of myostatin would potentially help increase lean muscle mass and reduce the fat mass.

In this study (8) it was determined that the different IGF-1 analogs, including IGF-1 LR3, counteracts with the negative effects of myostatin protein and helps prevent apoptosis, thereby protecting the muscle cells. Since IGF-1 LR3 has a longer half life than IGF-1 (further discussed below), the effects of IGF-1 LR3 were much more prominent.

Consequently, IGF-1 LR3 induces the effects of muscle hypertrophy, and thereby increases muscle mass. This demonstrates that this peptide can be potentially used in the treatment of muscle dystrophy or muscle loss and immobility.

Potential effects of IGF-1 LR3 on life span longevity

There have been several claims and possible controversies that IGF-1 and growth hormone treatment can potentially increase the lifespan of humans.

It is known that IGF-1 LR3 protects the muscle cells and helps in the maintenance of the body, making it a potential anti-aging and cellular protective agent.

Studies (9) were conducted on rodents with IGF-1 LR3, which demonstrated that the peptide is useful in preventing the progression of several ailments including muscle atrophy and dementia. While further studies are still ongoing, these studies demonstrate that, similar to growth hormone therapy, IGF-1 treatment can also potentially be used to decrease disability and prolong human life span.


There are some known cases of adverse events reported during IGF-1 therapy, which may be similar in the case of IGF-1 LR3 treatment, considering that it is an IGF-1 analog and induces similar effects.

These adverse events include, but may not be limited to the following (5):

  • Numbness, pain and swelling at the site of injection (most common)
  • Seizures
  • Joint pain
  • Swelling
  • Headaches
  • Hypoglycemia, insulin resistance
  • Jaw pain

IGF-1 LR3 Peptide profile

Pharmacokinetic studies

As mentioned earlier, IGF-1 LR3 is an alteration of IGF-1 as it contains arginine and an extended amino acid structure at its N-terminal, making it a long peptide composed of 80+ amino acids.

Because of this alteration, IGF-1 LR3 has an increased half-life of up to 20-30 hours versus the normal IGF-1 half-life of 12-15 hours (10) and has three times the potency of IGF-1 (2).

What’s more, IGF-1 LR3 has a poor binding affinity towards the IGF-1 receptors. Consequently, the peptide is easily distributed in the body organs in its natural form and results in faster plasma clearance than the normal IGF-1 (10).

Routes of administration – direct infusions vs. injections

This study (2) was conducted to determine the potency of the IGF-1 LR3 peptide and its effects to stimulate growth when administered via direct infusions and via injection route.

The study was conducted on normal, healthy rats and in experimentally treated rats with dexamethasone infusion to stimulate catabolic effects. IGF analogs were administered either via subcutaneous injections or through direct infusions for 7 consecutive days at a dose of 320 microg/day in normal rats and 400 microg/day in catabolic rats.

After the study, it was reported that the rats treated via direct infusions showed more significant results than the rats treated via the injected route. The effects of direct infusions were 3 times higher than those of the injected peptide.

In addition, IGF-1 LR3 was determined to be amongst the most potent IGF-1 analogs as they induced longer, better effects than IGF-1. The catabolic effects in the rats were also reversed at a higher rate when treated with IGF-1 LR3 than IGF-1.

Is IGF-1 LR3 approved by the FDA?

While IGF-1 has been clinically approved by the FDA in the US, there is sufficient data online to affirm that IGF-1 LR3 is not yet approved by the FDA. This is mainly because adequate clinical data to support IGF-1 LR3 use is not yet available.

Even so, IGF-1 LR3 is available on several online platforms for educational and research purposes only.


IGF-1 LR3 is a potent synthetic peptide protein that is composed of 80+ amino acids and is analogous to endogenous IGF-1 hormone.

The main mutation in this peptide is that IGF-1 LR3 contains arginine amino acid and an extended 13-amino acid structure at its N-terminal, due to which it exerts higher potency and bioavailability than the endogenous IGF-1.

Several research studies have shown that IGF-1 LR3 possesses various therapeutic effects and can potentially be used in treating ailments such as diabetes and IGF-1 growth hormone deficiency. However, clinical studies are yet to be conducted with this peptide to ensure safe use in humans.

Currently, IGF-1 LR3 is not approved by the FDA for clinical use, but it is available online for educational and research purposes.


1. Growth hormone, athletic performance, and aging. Harvard Health Publishing, Harvard Medical School.

2. Tomas, F. M., Knowles, S. E., Owens, P. C., Chandler, C. S., Francis, G. L., Read, L. C., & Ballard, F. J. (1992). Insulin-like growth factor-I (IGF-I) and especially IGF-I variants are anabolic in dexamethasone-treated rats. The Biochemical journal, 282 ( Pt 1)(Pt 1), 91–97.

3. Yakar, S et al., 40 YEARS OF IGF1: Insulin-like growth factors: actions on the skeleton (Jul 2018). Journal of Molecular Endocrinology, vol. 61 Issue 1.

4. Mohan S, Baylink DJ. IGF-binding proteins are multifunctional and act via IGF-dependent and -independent mechanisms. J Endocrinol. 2002 Oct;175(1):19-31.

5. Anderson, L. J., Tamayose, J. M., & Garcia, J. M. (2018). Use of growth hormone, IGF-I, and insulin for anabolic purpose: Pharmacological basis, methods of detection, and adverse effects. Molecular and cellular endocrinology, 464, 65–74.

6. IGF1 Deficiency, Recombinant Human Insulin-Like Growth Factor (rhIGF-1) Treatment of Short Stature Associated with IGF-1 Deficiency.

7. Assefa, B., Mahmoud, A. M., Pfeiffer, A., Birkenfeld, A. L., Spranger, J., & Arafat, A. M. (2017). Insulin-Like Growth Factor (IGF) Binding Protein-2, Independently of IGF-1, Induces GLUT-4 Translocation and Glucose Uptake in 3T3-L1 Adipocytes. Oxidative medicine and cellular longevity, 2017

8. Naisi Li, Qiyuan Yang, Ryan G. Walker, Thomas B. Thompson, Min Du, Buel D. Rodgers, Myostatin Attenuation In Vivo Reduces Adiposity, but Activates Adipogenesis, Endocrinology, Volume 157, Issue 1, 1 January 2016, Pages 282–291.

9. William E. Sonntag, Anna Csiszar, Raphael de Cabo, Luigi Ferrucci, Zoltan Ungvari, Diverse Roles of Growth Hormone and Insulin-Like Growth Factor-1 in Mammalian Aging: Progress and Controversies, The Journals of Gerontology: Series A, Volume 67A, Issue 6, June 2012, Pages 587–598,

10. Mario Thevis (13 December 2010). Mass Spectrometry in Sports Drug Testing: Characterization of Prohibited Substances and Doping Control Analytical Assays. John Wiley & Sons. pp. 252.

11. Rosenbloom AL. Mecasermin (recombinant human insulin-like growth factor I). Ad Ther. 2009 Jan; 26(1):40-54.


IGF-1 LR3 blog post

To get a detailed review and for references to some research studies on this IGF 1 peptide, read our latest IGF-1 LR3 Peptide – Review, Benefits, Side Effects blog post.

NOTE: These products are intended for laboratory research use only. IGF-1 LR3 for sale is not intended for personal use. Please review and adhere to our Terms and Conditions before ordering.