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Bioalmanac

IGF-1 LR3

Long R3 IGF-1 · LR3 · Long Arg3 IGF-1

Preclinical

Status reviewed 16 Aug 2026

Prohibited in sport

A modified insulin-like growth factor engineered to last far longer in the body than the natural hormone. It can cause hypoglycaemia, which makes it the most acutely dangerous compound on this site.

Storage

Freeze-dried powder
Refrigerated at 2–8 °C, protected from light.
After mixing
Refrigerated at 2–8 °C. Do not freeze once mixed. Larger proteins are less forgiving of temperature swings than short peptides.
Long-term, frozen
Unopened powder is stable at −20 °C or colder.

Reconstitution — 1 mg vial, 40 mcg dose

On a 1 mL U-100 syringe. Check every figure against your own vial before drawing.

Water addedConcentrationVolume to drawUnitsDoses per vial
1 mL1 mg/mL0.04 mL4 units25
2 mL0.5 mg/mL0.08 mL8 units25
3 mL0.333 mg/mL0.12 mL12 units25
5 mL0.2 mg/mL0.2 mL20 units25

Dose ranges reported in sources

Descriptions of what sources report, not recommendations.

GoalRangeFrequencySource
Commonly described community protocol20–50 mcgOnce dailyCommunity practice

When to stop

  • Any sign of low blood sugar: sweating, shaking, confusion, palpitations, sudden hunger, blurred vision. Take fast-acting carbohydrate immediately. If confusion or loss of consciousness occurs, this is an emergency. Call emergency services.
  • Repeated hypoglycaemic episodes, even mild ones. This is the compound telling you the dose is wrong, and the next episode may not be mild.
  • Any new lump, swelling or unexplained persistent pain.
  • Jaw pain, difficulty swallowing, or snoring that is new. All reported with the approved recombinant product.
  • Any allergic response: rash, hives, facial swelling or difficulty breathing. Seek urgent care.
  • Changes in vision that do not resolve.

Not approved for human use in any jurisdiction, and never studied in a human trial. Recombinant IGF-1 itself (mecasermin) is approved for severe primary IGF-1 deficiency, and its labelling carries an explicit hypoglycaemia warning. That warning is the closest thing to clinical safety information this class has.

Arithmetic on values you enter. Not medical advice. Not reviewed by a clinician. · bioalmanac.com/peptides/igf-1-lr3

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