Onset
Not established for this analogue.
Protocol / Research Dosing Guide
IGF-1 LR3 Dosage Guide: Reported Ranges, Vial Math and Safety
An evidence-organized IGF-1 LR3 reference that keeps research-community practice clearly separated from what published human research supports.
Last reviewed September 16, 202617 minute readResearch information only
Level 1–2 — Laboratory and animal evidenceNo human dose-finding trialNot FDA approved
IGF-1 LR3 Quick Start
IGF-1 LR3 is an engineered IGF-1 analogue modified so that it escapes most binding-protein capture, which extends its activity compared with native IGF-1. There is no approved human use and no dose-finding trial. The amounts discussed online are research-community practice, and the main documented hazard is hypoglycemia from insulin-receptor cross-activity.
Why researchers care
Anabolic signalling, tissue growth and recovery research
Class
Long R3 insulin-like growth factor 1, a modified IGF-1 analogue with reduced binding-protein affinity
Route reported
Subcutaneous or intramuscular in reported practice
Cycle length
Reported multi-week community blocks; not validated
Regulatory status
Not FDA approved
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IGF-1 LR3 Dosing Protocol and Schedule
The supplied source reports subcutaneous and intramuscular research-community ranges, community cycle structures, half-life claims and a 1 mg vial with 2 mL of bacteriostatic water as a calculator example. It presents these as observational, not as guidance.
| Phase or study | Amount | Frequency / evidence |
|---|---|---|
| Community reported block | Multi-week daily use described in community protocols | Community reported |
| Community reported frequency | Once daily is the most commonly described pattern | Community reported |
| Human validated schedule | Not established | Not established |
| Rest period | Community blocks describe off periods; no trial validates them | Not established |
No human study establishes an IGF-1 LR3 amount, frequency, block length or rest period. Everything reported here is observational.
IGF-1 LR3 Supplies Needed
Neutral research-material planning only. This does not establish an appropriate amount or route.
Research planning item
Exact labeled research vial
Research planning item
Bacteriostatic water at a measured volume
Research planning item
U-100 insulin syringes for very small draws
Research planning item
Alcohol prep swabs
Research planning item
Sharps container
Research planning item
Refrigeration for the prepared vial
Research planning item
Glucose monitoring capability given hypoglycemia risk
IGF-1 LR3 Reconstitution Calculator
Vial-format concentration math
Concentration
0.5 mg/mL
Draw volume
0.08 mL
U-100 units
8
Mathematical draws
25
Arithmetic only. The entered amount is not a recommendation and does not establish suitability.
Best Time to Take IGF-1 LR3: Morning or Night?
Time of day?
Not established. Community descriptions vary and no study compares timing.
Around training?
A community rationale, not a tested variable.
With food?
Community sources commonly describe carbohydrate availability because of hypoglycemia risk; this is a caution, not a protocol.
Missed amount?
No validated procedure exists.
IGF-1 LR3 Route Comparison
| Format | What is reported | Evidence limit |
|---|---|---|
| Subcutaneous | The most commonly described research-community route | No human pharmacokinetic study for this analogue |
| Intramuscular | Also described in community practice | Site-specific claims are not supported by evidence |
| Oral | Not viable | A protein of this size is destroyed by digestion |
Routes and amounts are not interchangeable unless a verified study explicitly establishes a conversion.
IGF-1 LR3 Half-Life and Dosing Frequency
| Measure | Finding | Evidence limit |
|---|---|---|
| Reported analogue half-life | Community sources describe a substantially longer active window than native IGF-1 | Not confirmed by a human study |
| Native IGF-1 comparison | Native IGF-1 is largely bound by binding proteins | The LR3 modification reduces that binding |
| Human pharmacokinetics | Not established | No human study identified for LR3 |
| Frequency logic | Once-daily use is a community convention | Not experimentally validated |
IGF-1 LR3 Dosage Chart
| Route | Amount | Frequency | Source | Human validation |
|---|---|---|---|---|
| Subcutaneous | Community reported micrograms per day | Once daily | Community report | No |
| Intramuscular | Community reported micrograms per day | Once daily | Community report | No |
| Human validated | Not established | Not established | No evidence | No |
Published study values describe those studies. Community-reported values are not validated dosing recommendations.
IGF-1 LR3 Reconstitution Guide
Concentration: 0.5 mg/mL
| Entered amount | Volume | U-100 units |
|---|---|---|
| 0.04 mg | 0.08 mL | 8 units |
| 0.08 mg | 0.16 mL | 16 units |
| 0.12 mg | 0.24 mL | 24 units |
- 1.Confirm the milligram total on the vial label; IGF-1 LR3 vials are usually 1 mg.
- 2.Record the exact bacteriostatic water volume added.
- 3.Clean the stopper with an alcohol swab.
- 4.Add liquid slowly along the vial wall.
- 5.Swirl gently; do not shake a protein solution.
- 6.Divide milligrams by millilitres. 1 mg in 2 mL is 0.5 mg/mL, so 40 mcg is 0.08 mL or 8 units.
- 7.Label the concentration and the preparation date.
- 8.Refrigerate and protect from light.
Reconstitution does not establish identity, purity, sterility, stability, or an appropriate amount.
How IGF-1 LR3 Works
Receptor target
IGF-1 LR3 activates the IGF-1 receptor and can cross-activate the insulin receptor.
IGF-1 LR3 Human Trials and FDA Status
Current status · verified September 16, 2026
Not FDA approved
- No published human dose-finding trial of IGF-1 LR3 was identified.
- IGF-1 LR3 is widely used as a laboratory cell-culture supplement, which is a manufacturing context, not human evidence.
- Mecasermin, a recombinant human IGF-1, is an approved medicine but is a different molecule with its own labeling.
- IGF-1 LR3 is not FDA approved and has no established medical use.
Who Should Avoid IGF-1 LR3?
This is an evidence-gap and precaution list, not an approved prescribing label.
Active or prior cancer
IGF-1 signalling promotes cell proliferation
Diabetes or hypoglycemia risk
Insulin-receptor cross-activity can lower blood glucose
Pregnancy or breastfeeding
No safety data
Children or adolescents
Growth-axis effects are not characterized for this analogue
Retinopathy or untreated endocrine disease
IGF-1 effects on these conditions are not characterized
IGF-1 LR3 Side Effects, Risks and Safety
HypoglycemiaMechanistically expected
Important limitation: The most frequently described hazard.
Injection-site reactionAnecdotal
Important limitation: No controlled incidence data.
Fluid retention or joint discomfortAnecdotal
Important limitation: Consistent with growth-axis effects but not quantified.
Proliferative riskMechanistic
Important limitation: IGF-1 signalling drives cell growth; human risk is not quantified.
Drug interactionsUnknown
Important limitation: No interaction studies for this analogue.
Long-term effectsUnknown
Important limitation: No follow-up evidence.
IGF-1 LR3 Timeline and Monitoring
Community block length
Multi-week structures are reported without validation.
Monitoring
Blood glucose awareness is the most frequently cited caution; no validated monitoring protocol exists.
Stopping rules
Not established.
IGF-1 LR3 Benefits and Results: What the Evidence Shows
| Claim | Evidence level | What research shows | Important limitation |
|---|---|---|---|
| Muscle or tissue growth | Not established in humans | Community reported | No human trial |
| Recovery | Not established in humans | Community reported | No human trial |
| Cell-culture proliferation | Established in laboratory use | Level 2 | Not a human outcome |
| Fat loss | Not established | Community claim | No evidence |
IGF-1 LR3 Storage and Handling
Unreconstituted vial
Follow the product label; keep cool, dry and out of light.
Prepared vial
Refrigerate; no validated LR3-specific stability window was identified.
Freezing
Repeated freeze-thaw cycles are avoided for protein solutions.
Appearance
Cloudiness, discoloration or particles mean the solution should not be used.
IGF-1 LR3 Troubleshooting
Draw volume is tiny
That is expected at 1 mg per vial; use a 0.3 mL U-100 syringe for readable units.
Feeling shaky, sweaty or light-headed
These are classic low-blood-sugar symptoms; treat glucose first and seek clinical review.
Units do not match a source table
Concentration differs with the liquid volume added; recompute from your own vial.
Solution appears cloudy
Stop and seek qualified product guidance.
Missed planned administration
No validated procedure exists.
IGF-1 LR3 Comparisons
| Compound | Class or mechanism | Evidence | FDA status |
|---|---|---|---|
| IGF-1 LR3 | Binding-protein-resistant analogue | No human trial | Not approved |
| Native IGF-1 (mecasermin) | Recombinant human IGF-1 | Approved for defined deficiency indications | Prescription only |
| IGF-1 DES | Short-acting analogue | Different reported profile | Not interchangeable |
IGF-1 LR3 Frequently Asked Questions
What is IGF-1 LR3?
An engineered IGF-1 analogue modified to escape most binding-protein capture.
Is it FDA approved?
No.
Is there a validated human dose?
No dose-finding trial exists.
Why is hypoglycemia the main caution?
IGF-1 can cross-activate the insulin receptor and lower blood glucose.
Is it the same as mecasermin?
No. Mecasermin is native recombinant IGF-1 and a different product.
What does 1 mg in 2 mL give?
0.5 mg/mL, so 40 mcg is 0.08 mL or 8 units on a U-100 syringe.
Does injection site direct growth to that muscle?
No evidence supports site-specific growth.
Is a cycle length established?
No.
Is cancer risk known?
Human risk is not quantified, but IGF-1 signalling promotes cell proliferation.
What does the calculator do?
Concentration and volume arithmetic only.
Is long-term safety known?
No.
Sources and Research
Coverage source
1. IGF-1 LR3 protocol coverage source
Supplied coverage source for reported ranges, cycles and vial arithmetic.
Open direct sourceRegulatory labeling
2. Mecasermin (recombinant human IGF-1) prescribing information
Approved IGF-1 labeling, included as regulatory contrast rather than LR3 evidence.
Open direct sourcePublished research
3. Long R3 IGF-1 binding-protein affinity and potency
Published characterization of the LR3 modification and its reduced binding-protein affinity.
Open direct sourceMissing information flagged for review
- Human dose: Not established
- Human half-life and bioavailability: Not established
- Validated cycle and rest period: Not established
- Quantified proliferative and long-term risk: Not established
- Interaction data: Not established