IGF-1 LR3
Long-acting IGF-1 analog — the highest-risk one in the GH group
Experimental material. Read before using anything from here.
Nothing on this page is a medical recommendation, prescription or treatment plan. It is an organized translation of protocols circulating in research communities and, where it exists, of what published trials tested. The two are marked differently — and they are not equivalent.
Most of the compounds here have no FDA approval for human use. Several are sold labeled "research use only", which means they have not gone through purity, sterility or dosage controls for human consumption. A community-reported dose is not a validated dose: it is what someone reported having done.
Talk to a licensed health professional before considering any of these compounds. If you already use one and feel anything unexpected, seek care — do not wait for the next routine test.
Summary
Synthetic, longer-acting analog of insulin-like growth factor 1. The body's own IGF-1 carries growth signals from the liver to muscle and bone; LR3 does the same, but resists the binding proteins, which greatly extends its activity.
Quick reference
- Route
- Subcutaneous or intramuscular only. There is no validated oral or topical form.
- Schedule
- 1×/day in planning, given the 20–30 h half-life.
- Dose context
- 20–100 mcg/day appears in community protocols. No human trial has validated a range.
- Status
- Not approved for any human use. Banned at all times by WADA.
IGF-1 LR3 Protocol Formats
| Phase | Daily dose | Frequency | Notes |
|---|---|---|---|
| Assessment | 20 mcg/day | 1×/day | Used to gauge tolerance and hypoglycemic response. |
| Low range | 20-40 mcg/day | 1×/day | Most-cited beginner range. Women in community sources often stay 10-20 mcg/day. |
| Moderate range | 40-80 mcg/day | 1×/day | Diminishing returns commonly reported above ~50-60 mcg/day. |
| High range | 80-100 mcg/day | 1×/day | Reported by advanced users; side-effect frequency rises. |
IGF-1 LR3 Protocol Formats
| Phase | Daily dose | Site | Notes |
|---|---|---|---|
| Assessment | 20 mcg/day | Trained muscle, post-workout | Identical glucose-monitoring rules apply as with SubQ. |
| Low-moderate | 20-50 mcg/day | Trained muscle, post-workout | Often used in research interest in localized hypertrophy signaling. |
| Moderate-high | 50-100 mcg/day | Trained muscle, post-workout | Side-effect frequency rises in the upper portion of the range. |
Cycle structure
| Approach | On-cycle | Off-cycle | Best for |
|---|---|---|---|
| Conservative | 3-4 weeks | 4-6 weeks | Lower-dose tolerance assessment in first cycles. |
| Standard | 4 weeks | 4 weeks minimum | Most-cited research-community structure. |
| Extended | 5-6 weeks | 6 weeks minimum | Used only after prior cycles confirmed glucose tolerance. |
IGF-1 LR3 Reconstitution Guide
| BAC water added | Concentration | 20 mcg dose | 40 mcg dose | 50 mcg dose | 80 mcg dose | 100 mcg dose |
|---|---|---|---|---|---|---|
| 1 mL | 1,000 mcg/mL | 0.02 mL (2 units) | 0.04 mL (4 units) | 0.05 mL (5 units) | 0.08 mL (8 units) | 0.10 mL (10 units) |
| 2 mL | 500 mcg/mL | 0.04 mL (4 units) | 0.08 mL (8 units) | 0.10 mL (10 units) | 0.16 mL (16 units) | 0.20 mL (20 units) |
| 3 mL | 333 mcg/mL | 0.06 mL (6 units) | 0.12 mL (12 units) | 0.15 mL (15 units) | 0.24 mL (24 units) | 0.30 mL (30 units) |
IGF-1 LR3 Reconstitution Guide
| BAC water added | Concentration | 20 mcg dose | 40 mcg dose | 50 mcg dose |
|---|---|---|---|---|
| 0.5 mL | 200 mcg/mL | 0.10 mL (10 units) | 0.20 mL (20 units) | 0.25 mL (25 units) |
| 1 mL | 100 mcg/mL | 0.20 mL (20 units) | 0.40 mL (40 units) | 0.50 mL (50 units) |
IGF-1 LR3 Timeline & What to Monitor
| Window | What is usually monitored | What it tells you |
|---|---|---|
| Week 1 | Fasting blood glucose, hypoglycemic symptoms, injection-site response | Hypoglycemia frequency was highest in the first month of Increlex treatment. Daily glucose checks in this window are the highest-yield monitoring. |
| Weeks 2-3 | Resting weight, waist circumference, fasting glucose trend | Identifies early water retention or unusual abdominal expansion. |
| Weeks 3-4 | Fasting insulin, fasting glucose, performance markers | Insulin trends are most informative around the 3-4 week mark in research-community reports. |
| End of cycle | Repeat fasting glucose, fasting insulin, waist circumference | Comparison vs. baseline. A clean off-cycle requires these to return to baseline before any subsequent cycle. |
| Off-cycle (4+ weeks) | Symptom resolution, fasting markers | Off-time is when insulin sensitivity and IGF-1 receptor sensitivity recover. |
IGF-1 LR3 vs IGF-1 DES vs HGH vs Mecasermin
| Feature | IGF-1 LR3 | IGF-1 DES (1-3) | HGH (Somatropin) | Mecasermin (Increlex) |
|---|---|---|---|---|
| Type | Synthetic IGF-1 analog | Truncated IGF-1 variant | Recombinant growth hormone | Recombinant native human IGF-1 |
| Amino acids | 83 | 67 | 191 | 70 (identical to endogenous IGF-1) |
| Half-life | 20-30 hours | ~20-30 minutes | 2-3 hours | ~5.8 hours |
| Receptor potency | ~3x native IGF-1 | ~10x native IGF-1 (locally) | Indirect (drives endogenous IGF-1) | 1x (it is native IGF-1) |
| Action | Systemic, long-acting | Localized, rapid | Systemic upstream cascade | Systemic, replacement therapy |
| Dosing frequency | 1×/day | 2-3x daily | 1-2x daily | 2×/day SubQ |
| Common dose context | 20-100 mcg/day (research) | 50-150 mcg/day split (research) | 2-8 IU/day (research) | 0.04–0.12 mg/kg 2×/day (clinical) |
| IGFBP binding | Very low | Very low | N/A (acts upstream) | Normal (full IGFBP affinity) |
| FDA status | Not approved | Not approved | FDA-approved (multiple indications) | FDA-approved (severe primary IGF-1 deficiency in pediatrics) |
| WADA status | Prohibited | Prohibited | Prohibited | Prohibited |
| Practical note | Long-acting IGF-1 analog with the most accumulated community data | Localized, rapid signaling; very short window | Broadest endocrine effect; clinical-grade product | The clinical reference compound for everything else in this column |
Storage and handling
The rules below apply to practically every lyophilized peptide in this reference. Where a compound has its own requirement, it appears in the table in the previous section.
- Lyophilized powder, sealed: refrigerator, between 2 and 8 °C, protected from light. Many tolerate room temperature for short transport periods, but that is tolerance, not a recommendation.
- After reconstitution: always refrigerated, between 2 and 8 °C. The stability window drops to days or a few weeks, depending on the compound.
- Never freeze after reconstituting. The freeze–thaw cycle degrades the peptide.
- Do not shake. Swirl the vial slowly. Shaking breaks the peptide chain.
- Bacteriostatic water down the wall of the vial, in a slow stream, not squirted directly onto the powder.
- Cloudy solution, with particles or a color change: discard. There is no recovery.
Lab tests and monitoring
This list is the one that appears recurrently in the source, with small variations by compound. It serves as a starting point for a conversation with a professional — not as a substitute for that conversation.
- Before starting: complete blood count, comprehensive metabolic panel, lipid panel, fasting glucose and HbA1c, TSH and free T4, blood pressure and resting heart rate.
- Depending on the compound: IGF-1 (GH axis), lipase and amylase (VIP and the incretin agonists), serum copper and ceruloplasmin (GHK-Cu and blends containing it), CRP.
- Reassessment: most protocols review between week 4 and week 8, and then every 8–12 weeks.
- Do not wait for the routine lab test in the face of abdominal pain, visual changes, a change in a mole, shortness of breath, asymmetric swelling or any new and persistent symptom. That is a reason to seek care, not a spreadsheet item.
Evidence limits
Data source: peptidedosingprotocols.com, accessed on September 3, 2026. Translation and organization in Portuguese are original work. No primary source (PubMed, trial registry, package insert) was checked in building this page — the check was against the secondary source, and that alone.