Side-by-side · Research reference

HexarelinvsIGF-1 LR3

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 1HUMAN-REVIEWED19/45 cited

BAnimal-StrongHUMAN-REVIEWED10/58 cited

Hexarelin

Hexapeptide GHRP · Cardio-tropic

100–200 mcgPer doseSmith 1996

Phase 1Evidence levelGhigo 1997

~70 minHalf-lifeSemenistaya 2010

SQ · Multiple sites · 1–3×/day

IGF-1 LR3

IGF-1 Analogue · Research

3–10×Potency vs IGF-I

Low IGFBPBinding affinity

ResearchStatus

Research only · SQ typical in animal models

01Mechanism of Action

Parameter

Hexarelin

IGF-1 LR3

Primary target

Ghrelin receptor (GHS-R1a) + cardiac CD36Smith 1996 Ghigo 1997

IGF-1 receptor (IGF-1R)McTavish 2009

Pathway

GHS-R1a → Gαq → Ca²⁺ → GH release. CD36 engagement → direct cardio-tropic actionGhigo 1997

IGF-1R → IRS-1 → PI3K/Akt → Cell proliferation, protein synthesis, anti-apoptosisMuhlbradt 2009

Downstream effect

Strong GH pulse + IGF-1 elevation; cardio-protective effects in animal MI modelsGhigo 1997

Enhanced cell proliferation, muscle anabolism, inhibition of apoptosis, increased telomerase activity

Feedback intact?

Yes initially; tachyphylaxis with chronic useGhigo 1997

No — exogenous IGF analogue bypasses GH-mediated regulation

Origin

Synthetic hexapeptide His-D-2-Methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂Smith 1996

Synthetic 83-AA analogue: 13-AA N-terminal extension + Arg substitution at position 3

Antibody development

—

02Dosage Protocols

Parameter

Hexarelin

IGF-1 LR3

Standard dose

100–200 mcg per injectionSmith 1996

—

Frequency

1–2× per day max (tachyphylaxis with chronic 3× daily)

—

Lower / starter dose

50 mcg per dose

—

Evidence basis

Phase 1 / Phase 2 trialsSmith 1996 Ghigo 1997

Animal / in vitro only

Duration

4–8 weeks on / 4–8 weeks off (tachyphylaxis mitigation)

—

Reconstitution

Bacteriostatic water

—

Timing

Pre-sleep + fasted preferred

—

Half-life

~70 minSemenistaya 2010

—

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

03Metabolic / Fat Loss Evidence

Parameter

Hexarelin

IGF-1 LR3

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

04Side Effects & Safety

Parameter

Hexarelin

IGF-1 LR3

Cortisol elevation

Modest at high dosesGhigo 1997

—

Prolactin elevation

Modest at high dosesGhigo 1997

—

Hunger

Strong appetite increase via ghrelin agonism

—

Tachyphylaxis

Receptor desensitisation with chronic dosingGhigo 1997

—

Cardiac effects

Direct cardio-tropic; potential benefit in MI but unstudied in humansGhigo 1997

—

IGF-1 elevation

Strong; monitor with chronic high-dose use

—

Cancer risk

Contraindicated in active malignancy (GH/IGF-1 axis)

—

Pregnancy / OB

Avoid

—

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

Absolute Contraindications

Hexarelin

·Active malignancy
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

IGF-1 LR3

·Active malignancy or history of cancer
·Not approved for human use

Relative Contraindications

Hexarelin

·Untreated diabetes
·Severe hyperprolactinemia

IGF-1 LR3

·Diabetes or glucose intolerance
·Family history of cancer

05Administration Protocol

Parameter

Hexarelin

IGF-1 LR3

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.

IGF-1 LR3 is not FDA-approved for human use. All administration data derives from animal or in vitro studies.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

Subcutaneous or intraperitoneal injection in animal models. In vitro: added directly to culture medium at concentrations of 10–1000 ng/mL.Thomas 2007

3. Timing

Pre-sleep + fasted preferred. Cycle on/off to avoid tachyphylaxis.

Lyophilised powder reconstituted in sterile water or buffered saline per manufacturer protocol. Store at 2–8 °C after reconstitution.

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.

Enhanced stability vs native IGF-1 due to reduced IGFBP binding; exact half-life in vivo not fully characterized in humans.

5. Needle

29–31G, 4–8 mm insulin syringe.

—

06Stack Synergy

Hexarelin

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

Hexarelin (GHRP) + CJC-1295-no-DAC (GHRH analogue) is the higher-amplitude variant of the standard GHRH+GHRP stack. Hexarelin produces a stronger pulse than ipamorelin but with cortisol + prolactin signal — choose this stack for maximum GH amplitude when side-effect tolerance is acceptable. Cycle aggressively.

Hexarelin: 100 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: Maximum GH pulse amplitude (with side-effect signal)

Smith 1996 Teichman 2006

IGF-1 LR3

+ GHRP-6

Multi-pathway

View GHRP-6 →

GHRP-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-pathway

View Ipamorelin →

Ipamorelin (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)