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This is plain-language harm-reduction information, not medical advice. Peptides discussed here are research compounds; most are not approved for human use. People will use them either way — we would rather they have the facts.
What it is
IGF-1 (insulin-like growth factor 1) is the hormone produced by the liver in response to growth hormone — it is responsible for most of GH's anabolic effects. IGF-1 LR3 is a synthetic version modified to last around three days in the body instead of minutes.
It is one of the most aggressive anabolic peptides in common use. Side-effect and safety profile reflects that.
History
Originally developed for laboratory cell-culture work in the 1990s. The "LR3" stands for "Long R3" — three modifications that extend its half-life and reduce binding to IGFBPs.
How it works
Binds the IGF-1 receptor and triggers anabolic signalling (cell growth, protein synthesis, glucose uptake into muscle).
Dosage
- 20–80 mcg daily.
- Cycle 4–6 weeks on, then break (receptors downregulate).
How it is taken
- Subcutaneous belly injection. Some users inject bilaterally near worked muscles, though systemic effect dominates.
How to reconstitute
- 1 mg vial with 2 ml BAC water = 500 mcg/ml. 40 mcg = 8 units on a 1 ml insulin syringe.
- Bacteriostatic water can degrade IGF-1 LR3 — some users prefer 0.6% acetic acid solution. Trade-off: stability vs comfort.
How it should arrive
White powder, sealed vial. Often shipped on cold pack.
How it should look once reconstituted
Clear colourless solution.
What to expect, and when
- Pump and muscle fullness: within days.
- Body composition changes: 2–4 weeks.
- Diminishing returns and receptor downregulation: 4–6 weeks.
Side effects
- Hypoglycaemia — IGF-1 LR3 increases glucose uptake into muscle. Eating regularly after dosing is critical.
- Increased hunger.
- Possible enlargement of internal organs at high doses over time.
- Lethargy in some users.
Risks
- Strong theoretical cancer-promotion concern — IGF-1 is a known cell-proliferation signal.
- Hypoglycaemia can become severe at higher doses.
- WADA prohibited.
Potential gains
- Rapid increases in muscle fullness and pump.
- Notable lean mass gains over 4-week cycles.
- Some users report joint discomfort improvement.
Other useful information
One of the most aggressive peptides on the market. The cancer-promotion concern is the most legitimate red flag of any peptide in this catalogue. Worth thinking hard about whether the gains justify the unknown.
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