Side-by-side · Research reference

IGF-1 LR3vsMOTS-c

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

BAnimal-StrongHUMAN-REVIEWED16/68 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

MOTS-c

Mitokine · Mitochondria-Encoded

5–10 mgWeekly doseLee 2015

AnimalEvidence levelLee 2015 Reynolds 2021

Min–hrsHalf-life

SQ · Variable · 2–3×/week

01Mechanism of Action

Parameter

IGF-1 LR3

MOTS-c

Primary target

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

Mitochondrial 12S rRNA sORF → folate-AICAR-AMPK axisLee 2015

Pathway

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

Folate cycle inhibition → ↑AICAR → AMPK phosphorylation → PGC-1α upregulationLee 2015 Kim 2018

Downstream effect

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

Enhanced fatty acid oxidation, GLUT4-mediated glucose uptake, mitochondrial bioenergetics, anti-inflammationLee 2015

Feedback intact?

No — exogenous IGF analogue bypasses GH-mediated regulation

Stress-responsive, AMPK-dependent nuclear translocationKim 2018

Origin

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

Endogenous 16-AA mitokine; mtDNA-encoded; declines with age; upregulated by exerciseReynolds 2021

Antibody development

—

02Dosage Protocols

Parameter

IGF-1 LR3

MOTS-c

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.

—

Evidence basis

Animal / in vitro only

Animal + anecdotalLee 2015 Reynolds 2021 A first-in-human phase 1 study 2021

Phase 1a/1b CB4211 analog trial completed 2021; no native MOTS-c RCT published.

Human use

Not FDA-approved; no published human trials

—

Standard dose

—

5–10 mg / weekLee 2015

Experimental, extrapolated from animal data. No human RCT-derived dose.

Frequency

—

2–3× per week

Short half-life may necessitate more frequent dosing for saturation.

Lower / starter dose

—

2.5–5 mg / week

Recommended due to limited human data.

Duration

—

4–12 weeks (experimental)

Optimal cycle length unknown.

Reconstitution

—

Bacteriostatic water, 1–2 mL

10 mg/mL at 1 mL.

Timing

—

Pre-workout or fasted state preferred

Activity-context amplifies AMPK response.

Half-life

—

Minutes to hours (estimated)

Systemically unstable; native MOTS-c PK in humans not fully characterised.

03Metabolic / Fat Loss Evidence

Parameter

IGF-1 LR3

MOTS-c

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

—

Diet-induced / metabolic obesity; systemic fat utilization

Quantified reduction

—

Significant HFD fat gain ↓Lee 2015

Murine models, dose-dependent (5 & 15 mg/kg).

IGF-1 impact

—

No direct IGF-1 pathway; AMPK-mediated

Effect on lean mass

—

High dose significantly ↑ lean mass in mice

Insulin sensitivity

—

Reversed HFD insulin resistance in 7 days (mice)Lee 2015

Triglycerides

—

AMPK-driven FA oxidation suggests TG benefit (not directly measured)

Glucose metabolism

—

Improved glucose tolerance; GLUT4 upregulationLee 2015

Effect reversibility

—

Unknown — no long-term follow-up data

Context dependency

—

No effect in normal-chow mice; requires metabolic stressReynolds 2021

Key publication

—

Lee Cell Metab 2015 · Reynolds Nat Commun 2021 · Kim Cell Metab 2018Lee 2015 Reynolds 2021 Kim 2018

04Side Effects & Safety

Parameter

IGF-1 LR3

MOTS-c

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

—

Mild irritation (reported)

Fluid retention / Edema

—

Not reported

Glucose intolerance

—

Improves glucose toleranceLee 2015

Cardiovascular

—

Heart palpitations (anecdotal); cardiac hypertrophy reversed in diabetic rats

Cancer risk

—

Contradictory data — some models suggest pro-proliferative effects

CNS / Neurological

—

Insomnia, headache (anecdotal reports)

GI symptoms

—

Nausea, stomach discomfort (reported)

Antibody formation

—

No data (no long-term human trials)

Pregnancy / OB

—

Avoid — insufficient safety data

Evidence quality

—

Phase 1 analog (CB4211); preclinical; anecdotal humanA first-in-human phase 1 study 2021

Absolute Contraindications

IGF-1 LR3

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

MOTS-c

·Pregnancy / breastfeeding (insufficient data)

Relative Contraindications

IGF-1 LR3

·Diabetes or glucose intolerance
·Family history of cancer

MOTS-c

·Active cancer or cancer predisposition
·AMPK pathway deficiency (efficacy nullified)
·Use with cancer-promoting medications (theoretical)

05Administration Protocol

Parameter

IGF-1 LR3

MOTS-c

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 1–2 mL bacteriostatic water. At 10 mg/vial, 1 mL gives 10 mg/mL concentration. Roll gently to dissolve.

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, thigh, or deltoid. Rotate sites to avoid lipohypertrophy. Pinch fat layer.

3. Reconstitution (research)

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

Pre-workout or fasted state preferred — metabolic context amplifies AMPK response. 2–3× per week.

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, protected from light. Reconstituted: refrigerate, use within 21–30 days. Short systemic stability.

5. Needle

—

27–31G insulin syringe. Short needle (4–6 mm) for SQ delivery. Clean technique mandatory.

06Stack Synergy

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)

MOTS-c

+ Ipamorelin

Moderate

View Ipamorelin →

MOTS-c activates AMPK/PGC-1α for mitochondrial efficiency and fatty acid oxidation; ipamorelin stimulates GH for anabolic recovery and sleep depth. Pathways are complementary — MOTS-c handles metabolic flexibility and glucose handling while ipamorelin drives recovery and body recomposition through GH. Theoretical synergy is high; clinical data is lacking.

MOTS-c: 5 mg SQ · pre-workout (2–3×/wk)
Ipamorelin: 200–300 mcg SQ · pre-sleep (daily)
Primary benefit: Metabolic flexibility + GH recovery + ROS reduction