IGF-1 LR3
Also known as: Long R3 IGF-1, Insulin-like Growth Factor-1 Long R3
IGF-1 LR3 is a modified version of insulin-like growth factor-1 (IGF-1) with a longer half-life. The modifications make it more potent and prevent binding to IGF-binding proteins, allowing it to remain active in the body longer. It promotes muscle growth and fat loss.
Beginner Basics
Plain-English guide to IGF-1 LR3
What it does
IGF-1 LR3 is a modified growth factor that stays active in your body longer than natural versions. Researchers use it to study muscle growth, fat loss, and faster recovery after workouts.
Typical dose
Researchers typically use 20-100 micrograms per day, injected under the skin or into muscle, for a maximum of 4 weeks. Start at the lower end (20-40 micrograms) since it's very potent.
When to inject
Best used right after your workout. Keep fast-acting carbs (juice, candy) nearby since this can lower blood sugar.
Storage
Keep the dry powder in the refrigerator away from heat. Once mixed with water, it must stay refrigerated and is very temperature-sensitive.
First-timer tip
Start with the lowest dose and never exceed 4 weeks of use-this peptide is strong and extended use can cause side effects like low blood sugar.
On This Page
Research Status
Research compound - not FDA approved
For research purposes only. Not approved for human use. Not medical advice.
Research Areas
Side Effects
IGF-1 LR3 dramatically increases glucose uptake in muscle tissue, lowering blood glucose. Symptoms include tremor, sweating, dizziness, confusion, and rapid heartbeat. Manage by consuming fast-acting carbohydrates (glucose tablets, juice, honey) immediately. Always have carbs available during and after injection. Avoid fasting during the first 2-4 hours post-injection. Monitor blood glucose if diabetic or pre-diabetic.
IGF-1 LR3 stimulates rapid tissue growth, including connective tissue, which can cause joint discomfort, particularly in the knees, shoulders, and wrists. This is typically self-resolving and mild. Manage with rest, ice, and NSAIDs if needed. Ensure adequate hydration and electrolyte intake. Symptoms usually resolve within days of discontinuation.
Rapid growth of connective tissue in the wrist can compress the median nerve, causing numbness, tingling, or pain in the hand. This is more common with prolonged use beyond 4 weeks. Manage by wearing a wrist splint at night, reducing injection frequency, or discontinuing use. Symptoms typically resolve within 1-2 weeks of stopping the peptide.
Repeated injections at the same site cause localized fat loss (lipoatrophy) or, less commonly, fat gain (lipohypertrophy). This is cosmetic and reversible. Prevent by strictly rotating injection sites with each dose, maintaining at least 1-1.5 inches between injection points, and avoiding the same site more than once per week. Affected areas typically normalize within 3-6 months of proper rotation.
Local inflammation, erythema, or pruritus at the injection site can occur due to the peptide itself or improper injection technique. Manage by ensuring proper site rotation, using sterile technique, and allowing the solution to reach room temperature before injection. Apply ice if swelling occurs. Reactions typically resolve within 24 hours.
Mild to moderate headaches have been reported, possibly related to rapid metabolic changes or hypoglycemia. Manage by ensuring adequate carbohydrate intake post-injection and staying well-hydrated. Headaches typically resolve within hours.
Mild nausea can occur, particularly if injected on an empty stomach or if hypoglycemia develops. Manage by eating a small meal 30-60 minutes before injection and consuming carbohydrates post-injection. Nausea is typically transient.
Mild peripheral edema or water retention can occur due to increased protein synthesis and metabolic activity. Manage by maintaining adequate hydration and electrolyte balance. Edema typically resolves within days of discontinuation.
Prolonged IGF-1 LR3 use beyond 4 weeks can cause acromegaly-like changes including jaw enlargement, hand/foot growth, and facial coarsening. These changes are largely irreversible. Strictly adhere to the 4-week maximum cycle length. Discontinue immediately if any signs of acromegaly develop.
Chronic IGF-1 elevation can stimulate growth of internal organs (heart, liver, kidneys) and increase cancer risk. This is a theoretical concern with prolonged use. Limit use to 4-week cycles with extended breaks (at least 4-8 weeks) between cycles. Do not exceed recommended dosages or cycle duration.
Anaphylaxis or severe allergic reactions are rare but possible. Symptoms include difficulty breathing, throat tightness, severe rash, or swelling of face/lips. Seek emergency medical attention immediately if these occur. Have an epinephrine auto-injector available if you have a history of peptide allergies.
Dosing Reference
| Parameter | Value |
|---|---|
| Dose range | 20-100 mcg |
Frequency, timing and route - members only | |
Research disclaimer
Figures drawn from published research literature and community logs. Not clinical recommendations. Consult a qualified professional. Research use only.
Reconstitution Guide
Do not use saline or bacteriostatic saline, use only bacteriostatic water for reconstitution
Do not shake the vial vigorously; gentle swirling prevents peptide degradation
Discard immediately if the solution appears cloudy, discolored, or contains visible particles
Use within 30 days of reconstitution when stored at 2-8°C
Do not freeze the reconstituted solution; freezing may denature the peptide
Use the PeptideVolt reconstitution calculator for your exact concentration
Molecular and Pharmacological Data
| Molecular weight | 8949 |
| Half-life | 20-30 hours (compared to 10-20 minutes for native IGF-1) |
| Sequence | Members only |
IGF-1 LR3 is a synthetic analog of insulin-like growth factor-1 (IGF-1) engineered with an extended N-terminus (13 amino acids added) and arginine substitution at position 3, which dramatically increases its half-life and reduces binding to IGF-binding proteins (IGFBPs). This allows IGF-1 LR3 to remain bioactive in circulation 20-30 times longer than native IGF-1, promoting sustained anabolic signaling through the IGF-1 receptor. It stimulates protein synthesis, inhibits protein breakdown, enhances glucose uptake, and promotes lipolysis, resulting in lean muscle gain and fat loss.
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Recent Research
Recombinant expression of IGF-1 and LR3 IGF-1 fused with xylanase in Pichia pastoris.
IGF-1 has plaque-stabilizing effects in atherosclerosis by altering vascular smooth muscle cell phenotype.
Novel insulin-like growth factor-methotrexate covalent conjugate inhibits tumor growth in vivo at lower dosage than methotrexate alone.
Source: PubMed / NCBI. Updated daily. Articles are listed for research reference only.
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