Overview
IGF-1 LR3 (Long R3 IGF-1) is an engineered 83-amino-acid analogue of human IGF-1 featuring an amino acid substitution and a 13-amino-acid N-terminal extension.
What problem it targets: It targets sluggish muscle recovery, plateaued lean muscle accrual, muscular atrophy, and stubborn body fat storage.
What It Does
• Evades inhibitory binding proteins: Does not bind to IGF-binding proteins (IGFBPs), allowing it to remain completely free and biologically active in circulation for over 20 to 30 hours.
• Forces nutrients into muscle tissue: Strongly enhances cellular glucose and amino acid uptake into muscle cells rather than fat tissue, acting as a potent nutrient partitioning agent.
• Stimulates satellite cell proliferation: Drives the creation and fusion of new muscle satellite cells into mature fibers, facilitating long-term muscle remodeling.
• Realistic expectations: Produces intense muscle fullness and pumps within days. Injected once daily; cycles are typically limited to 4 to 6 weeks to prevent receptor desensitization and hypoglycemia.
Reconstitution
| Vial size | BAC water / Solvent | Concentration |
|---|---|---|
| 0.1 mg | + 0.2 mL acetic acid | 0.5 mg/mL |
| 1 mg | + 2 mL acetic acid | 0.5 mg/mL |
Solubility & Preparation Notes
The IGF-1 family has an isoelectric point right around neutral pH (~7.0). In plain BAC water, IGF-1 molecules rapidly unfold, adhere to the glass walls of the vial, aggregate, and degrade within days.
Solution: They require an acidic pH (0.6% acetic acid) to remain stable and biologically active in solution.
Step 1 — Solubilize (The Acid Step):
Draw 0.5 mL of sterile 0.6% acetic acid.
Inject it slowly down the inside glass wall of the vial (never spray directly onto the lyophilized cake).
Gently roll the vial between your palms until the liquid is 100% crystal clear.
Verification: Do not add BAC water while the solution is still hazy or clumped. It must be completely transparent first.
Step 2 — Dilute (The BAC Water Top-Off):
Once completely dissolved and clear, add the remaining volume of standard Bacteriostatic Water required by your dosing math.
Why this works: The acetic acid establishes the charge state needed to break the peptide apart into solution; the remaining BAC water dilutes the acid concentration down so it will not sting or irritate tissue upon injection.
Step 3 — Note on reconstituting the entire vial with Acetic Acid:
Users can choose to reconstitute the entire vial using only 0.6% acetic acid if they prioritize maximum long-term chemical stability (standard practice for extended IGF-1 storage). However, note that injecting an unbuffered, full-acid solution will cause a noticeable local sting and burning sensation at the injection site.
Protocol
| Phase | Frequency | Dose | Notes |
|---|---|---|---|
| Standard | Daily post-workout | 50 mcg | Systemic dose. |
| Site IM | Post-workout | 25–40 mcg/site | Local muscle. |
| Off | Equal to on-time | – | Mandatory. Cycle: 4–6 weeks on, equal time off. Off periods critical, receptor desensitises permanently if skipped. Timing: With food, post-workout; long half-life means hypoglycemia risk all day. Evidence: LR3 is not FDA-approved in any form (mecasermin ≠ LR3); no human dosing data. Women: Direct IGF-1 bypasses GH, so estrogen doesn’t soften it; same growth-signal caution: breast, ovarian, or uterine history. Men: Same growth-signal caution, prostate; watch PSA in men over ~40. |
Handling & Stacking
- Muscle fullness within days, recovery by 2–4 wks.
- Hypoglycaemia risk, keep fast carbs handy; off-cycles mandatory.
- Supply math 0.1mg → 14 vials | 1mg → 2 vials (4-wk @ 50 mcg × 7/wk)
Safety & Patient Education
- Intracranial hypertension with somatropin (papilledema, vision changes, headache, nausea, vomiting) Insulin resistance and new-onset T2DM Fluid retention, edema, carpal tunnel Pancreatitis (rare) IGF-1 elevation above age range carries theoretical malignancy risk 20–30 hour half-life means hypoglycemia risk extends throughout the day.
- Long-term IGF-1 elevation theoretical malignancy concern.
- IGF-1 (baseline / Wk 8 / end; you're dosing it directly, so this tracks exposure), Fasting glucose (Wk 0/4/8) Lipid panel (Wk 0/12) Hip/scoliosis exam in pediatrics Out of range?
- IGF-1 above your age range = too much growth signal → drop the dose.
- Hypoglycemia is the real acute risk and LR3's long half-life drags it out for hours – dose with food/carbs, keep fast sugar handy; shaky, sweaty, or foggy = treat it right away.
