Side-by-side · Research reference
IGF-1 LR3vsTesamorelin
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
AAnimal-StrongHUMAN-REVIEWED10/58 cited
BFDA-ApprovedFlagship27/68 cited
IGF-1 LR3
IGF-1 Analogue · Research
3–10×Potency vs IGF-I
Low IGFBPBinding affinity
ResearchStatus
Research only · SQ typical in animal models
Tesamorelin
GHRH Analogue · FDA-Approved
SQ · Abdomen · Once Daily
01Mechanism of Action
Parameter
IGF-1 LR3
Tesamorelin
Primary target
IGF-1 receptor (IGF-1R)McTavish 2009
Hypothalamic GHRH receptorsEGRIFTA® (tesamorelin for inje 2010
Pathway
IGF-1R → IRS-1 → PI3K/Akt → Cell proliferation, protein synthesis, anti-apoptosisMuhlbradt 2009
GHRH → Pituitary GH release → Liver IGF-1 synthesisFalutz 2007
Downstream effect
Enhanced cell proliferation, muscle anabolism, inhibition of apoptosis, increased telomerase activity
Increased GH pulsatility, elevated IGF-1, lipolysis of visceral adipose tissueFalutz 2010
Feedback intact?
No — exogenous IGF analogue bypasses GH-mediated regulation
Yes — physiological pulsatility preserved
Origin
Synthetic 83-AA analogue: 13-AA N-terminal extension + Arg substitution at position 3
Synthetic 44-AA GHRH analogue with trans-3-hexenoic-acid modification for stabilityEGRIFTA® (tesamorelin for inje 2010
02Dosage Protocols
Parameter
IGF-1 LR3
Tesamorelin
Research dose (animal models)
Variable by protocol and species
In vivo murine atherosclerosis studies used sustained delivery.
—
In vitro typical concentration
10–1000 ng/mLThomas 2007
Dose-dependent effects on follicle growth and estradiol production.
—
Half-maximal stimulation
0.6 nM LR3 vs 1.5 nM native IGF-1Price 2004
2.5-fold greater potency in lung fibroblast proliferation.
—
Human use
Not FDA-approved; no published human trials
—
Frequency
—
Once daily (morning or pre-sleep)
Aligns with natural GH pulse.
Duration
—
12–52 weeks
VAT returns within months of stopping.
Reconstitution
—
Sterile water per labeling
Preserved at 2–8 °C after reconstitution.
Timing
—
Empty stomach, pre-sleep preferred
03Metabolic / Fat Loss Evidence
Parameter
IGF-1 LR3
Tesamorelin
Mechanism
IGF-1R activation → lipolytic signaling; secondary to anabolic effects
—
Direct lipolytic evidence
Minimal — primarily anabolic/anti-apoptotic in literature
—
Atherosclerotic plaque effects
Reduced stenosis and core size in ApoE-KO micevon 2011
Plaque stabilization via vSMC phenotype modulation, not direct fat loss.
—
Human data
None published
—
Primary fat target
—
Visceral adipose tissue (VAT) — abdominal
Effect on lean mass
—
Modest lean mass preservation / slight increase
Effect reversibility
—
VAT returns within months of stopping
Key publication
—
Falutz et al. NEJM 2007 · Falutz JCEM 2010 · FDA approval 2010Falutz 2007Falutz 2010EGRIFTA® (tesamorelin for inje 2010
04Side Effects & Safety
Parameter
IGF-1 LR3
Tesamorelin
Hypoglycemia risk
Theoretical — IGF-1 analogues can lower blood glucose
—
Excessive cell proliferation
Mitogenic signaling; theoretical tumor promotion risk
—
Telomerase activation
2–10-fold increase in prostate cancer cells (PC-3, DU-145, LAPC-4)Wetterau 2003
Critically involved in cancer cell immortalization.
—
Oocyte degeneration
Increased oocyte degeneration at high doses (≥1000 ng/mL) in bovine folliclesThomas 2007
—
Unregulated anabolism
Bypasses physiological GH/IGF-1 feedback; no pulsatility control
—
Unknown human safety profile
No published human trials; safety data absent
—
Injection site reaction
—
Erythema, pruritus, redness (common)
Fluid retention / Edema
—
Peripheral edema, arthralgia, carpal tunnel (GH-axis effect)
IGF-1 elevation
—
Dose-dependent; supraphysiological levels = discontinue
Cancer risk
—
Contraindicated in active malignancy (GH/IGF-1 axis); theoretical tumour growth riskEGRIFTA® (tesamorelin for inje 2010
Antibody formation
—
~50% at 26 weeks; non-neutralising in most; rare hypersensitivity (<1%)Sévigny 2018
GI symptoms
—
Nausea, diarrhea (mild, transient)
Absolute Contraindications
IGF-1 LR3
- ·Active malignancy or history of cancer
- ·Not approved for human use
Tesamorelin
- ·Active malignancy or history of treated cancer
- ·Pregnancy
- ·Hypersensitivity to tesamorelin or mannitol
- ·Disruption of hypothalamic-pituitary axis (trauma, tumour, radiation)
Relative Contraindications
IGF-1 LR3
- ·Diabetes or glucose intolerance
- ·Family history of cancer
Tesamorelin
- ·Untreated diabetes (monitor HbA1c)
- ·Severe carpal tunnel syndrome
- ·Acute critical illness
05Administration Protocol
Parameter
IGF-1 LR3
Tesamorelin
1. Research use only
IGF-1 LR3 is not FDA-approved for human use. All administration data derives from animal or in vitro studies.
Add 2.1 mL sterile water to 2 mg lyophilised vial. Roll gently — do not shake. Solution should be clear.
2. Typical research route
Subcutaneous or intraperitoneal injection in animal models. In vitro: added directly to culture medium at concentrations of 10–1000 ng/mL.Thomas 2007
Subcutaneous — abdomen preferred. Rotate sites (avoid same spot within 2 cm). Avoid navel and waistband area.
3. Reconstitution (research)
Lyophilised powder reconstituted in sterile water or buffered saline per manufacturer protocol. Store at 2–8 °C after reconstitution.
Once daily. Preferred: evening, 2–3 hrs post-meal, before sleep — aligns with natural GH secretion pulse.
4. Stability
Enhanced stability vs native IGF-1 due to reduced IGFBP binding; exact half-life in vivo not fully characterized in humans.
Lyophilised: room temp, light-protected. Reconstituted: refrigerate 2–8 °C, use within 21 days.
5. Needle
—
27–31G, 4–8 mm insulin syringe. Pinch skin, 45° angle for lean individuals.
06Stack Synergy
IGF-1 LR3
+ GHRP-6
Multi-pathwayGHRP-6 stimulates endogenous GH release, which drives hepatic IGF-1 synthesis. IGF-1 LR3 provides exogenous, IGFBP-resistant IGF signaling. Combining upstream GH stimulation with downstream IGF receptor activation creates a dual-pathway anabolic effect. However, this bypasses natural feedback and carries compounded mitogenic risk.
- GHRP-6
- 100–200 mcg SQ · 2–3× daily
- IGF-1 LR3
- Research doses variable · post-workout typical in animal models
- Note
- Research context only — no human protocols exist
- Primary benefit
- Theoretical maximal anabolic signaling (GH + IGF axes)
+ Ipamorelin
Multi-pathwayIpamorelin (selective GHRP) stimulates pulsatile GH release without cortisol/prolactin elevation. IGF-1 LR3 directly activates IGF-1R independent of GH. This stack targets both upstream (GH secretion) and downstream (IGF receptor) nodes but eliminates physiological feedback, raising safety concerns around unchecked proliferation.
- Ipamorelin
- 200–300 mcg SQ · evening
- IGF-1 LR3
- Research doses only · timing variable
- Caution
- No human data; animal/in vitro only
- Primary benefit
- Dual-axis anabolic signaling (theoretical)
Tesamorelin
+ Ipamorelin
StrongTesamorelin (GHRH analogue) and ipamorelin (GHRP / ghrelin mimetic) act on two distinct receptor systems to amplify GH release synergistically — GHRH receptor + ghrelin receptor. This dual-axis stimulation produces a more robust, sustained GH pulse than either alone while maintaining physiological pulsatility. Ipamorelin is highly selective with minimal cortisol or prolactin elevation, making it the preferred GHRP pairing.
- Tesamorelin
- 2 mg SQ · evening
- Ipamorelin
- 200–300 mcg SQ · same injection
- Frequency
- Once daily, pre-sleep
- Primary benefit
- Maximal GH pulsatility, fat loss, recovery, sleep quality