What is the difference between IGF-1 LR3 and Tesamorelin?

IGF-1 LR3: IGF-1 LR3 (Long Arg3 IGF-1) is a synthetic analogue of Insulin-like Growth Factor 1 with an amino acid substitution at position 3 and a 13-amino acid N-terminal extension. These modifications prevent binding to IGF-binding proteins (IGFBPs), dramatically extending its half-life from ~12 minutes (native IGF-1) to approximately 20–30 hours. IGF-1 LR3 is widely used in research for its ability to promote cellular growth, protein synthesis, hyperplasia, and nutrient uptake into muscle tissue. Tesamorelin: Tesamorelin is an FDA-approved synthetic analog of growth hormone-releasing hormone (GHRH). Approved in 2010 as Egrifta, it is the only GHRH peptide with an approved clinical indication — reduction of excess visceral abdominal fat in people with HIV-associated lipodystrophy. It has the most robust human trial evidence of any growth hormone secretagogue, including dedicated studies on visceral fat and liver fat. Both are in the Performance & Growth Hormone category but differ in mechanism, dosing, and research evidence — see the full comparison.

Can you take IGF-1 LR3 and Tesamorelin together?

There is no specific, well-documented interaction rule for combining IGF-1 LR3 and Tesamorelin in the aggregated research reviewed. Combining peptides should only be considered under professional supervision. This is not medical advice.

Which is better researched, IGF-1 LR3 or Tesamorelin?

IGF-1 LR3 is currently research-stage and Tesamorelin is fda-approved. "Better researched" depends on your research goal — review each profile's cited sources.

Performance & Growth Hormone · Comparison

IGF-1 LR3 vs Tesamorelin

A neutral, side-by-side comparison of two performance & growth hormone peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.

IGF-1 LR3

Research-stage

IGF-1 LR3 (Long Arg3 IGF-1) is a synthetic analogue of Insulin-like Growth Factor 1 with an amino acid substitution at position 3 and a 13-amino acid N-terminal extension. These modifications prevent binding to IGF-binding proteins (IGFBPs), dramatically extending its half-life from ~12 minutes (native IGF-1) to approximately 20–30 hours. IGF-1 LR3 is widely used in research for its ability to promote cellular growth, protein synthesis, hyperplasia, and nutrient uptake into muscle tissue.

Full profile

Tesamorelin

FDA-approved

Tesamorelin is an FDA-approved synthetic analog of growth hormone-releasing hormone (GHRH). Approved in 2010 as Egrifta, it is the only GHRH peptide with an approved clinical indication — reduction of excess visceral abdominal fat in people with HIV-associated lipodystrophy. It has the most robust human trial evidence of any growth hormone secretagogue, including dedicated studies on visceral fat and liver fat.

Full profile

	IGF-1 LR3	Tesamorelin
Category	Performance & Growth Hormone	Performance & Growth Hormone
Also known as	Insulin-like Growth Factor-1 Long R3, Long R3 IGF-1, Increlex (human equivalent)	Egrifta, Egrifta SV, TH9507, GHRH analog
Evidence	Research-stage	FDA-approved
Dosing range	20mcg–100mcg mcg, Once daily post-workout, on training days only (common protocol)	1.28mg–2mg mg, once daily (subcutaneous)
Administration	Subcutaneous injection, Intramuscular injection (into the trained muscle — site-specific protocols)	Subcutaneous injection (abdomen, with site rotation)
Key side effects	Hypoglycemia (clinically significant — monitor blood sugar carefully), Jaw and organ growth with chronic high-dose use (theoretical at research doses), Fatigue and headaches, Joint pain	Injection site reactions (erythema, pruritus), Peripheral edema, Arthralgia (joint pain), Myalgia
Cited sources	3 references	5 references

Key differences

Evidence level differs: IGF-1 LR3 is research-stage, while Tesamorelin is fda-approved.
Administration: IGF-1 LR3 — Subcutaneous injection, Intramuscular injection (into the trained muscle — site-specific protocols); Tesamorelin — Subcutaneous injection (abdomen, with site rotation).
Dosing units differ: IGF-1 LR3 is dosed in mcg, Tesamorelin in mg — they operate at different scales.
Frequency: IGF-1 LR3 is typically Once daily post-workout, on training days only (common protocol); Tesamorelin is once daily (subcutaneous).
Research depth: this profile cites 3 sources for IGF-1 LR3 vs 5 for Tesamorelin.

How each works

IGF-1 LR3

In vitro and animal research establishes IGF-1 LR3 as a potent anabolic and growth-promoting agent. It activates the IGF-1 receptor (IGF-1R) and downstream PI3K/Akt and MAPK/Erk pathways, promoting skeletal muscle hypertrophy and satellite cell activation. Its extended half-life makes it far more active systemically than native IGF-1. Research also documents its role in connective tissue repair, nerve regeneration, and fat oxidation. Human research is limited — most data comes from cancer cell biology and athletic performance settings.

Tesamorelin

Tesamorelin stimulates pulsatile growth hormone (GH) release from the pituitary, raising serum IGF-1 and preferentially reducing visceral adipose tissue (VAT). FDA-registration trials (Falutz et al., NEJM 2007; JAIDS 2010) showed ~15% VAT reduction versus placebo over 26 weeks. Later randomized trials (Stanley et al., JAMA 2014; Lancet HIV 2019) extended the evidence to liver fat, showing meaningful reductions in hepatic fat fraction and attenuated fibrosis progression in HIV-associated NAFLD.

Read the full IGF-1 LR3 profile Read the full Tesamorelin profile

This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.