IGF-1 LR3 Dosing, Need to Know Information, Safety, Stacks, Dosing Calculator and more!
How much do I take? Is this right for me? How do I use it? Is it safe? How do I know it's working? Compound Profile Scientific & Efficacy Data C400H625N111O115S9 Molecular Formula 9111.4 g/mol Molecular Weight 20-30 hours Half-Life High when injected subcutane
How much do I take?
Is this right for me?
How do I use it?
Is it safe?
How do I know it's working?
Compound Profile
Scientific & Efficacy Data
C400H625N111O115S9
Molecular Formula
9111.4 g/mol
Molecular Weight
20-30 hours
Half-Life
High when injected subcutaneously or intramuscularly
Bioavailability
946870-92-4
CAS #
Not assigned
PubChem Status
Developed By · 1987
Francis John Ballard and colleagues
CSIRO Division of Human Nutrition, Adelaide, Australia
Primary Benefits
One of the most potent peptides for muscle building through both hypertrophy and hyperplasia mechanisms
Significantly accelerates post-workout recovery and tissue repair, allowing more frequent intense training
Enhances how efficiently your body uses protein and carbohydrates for muscle building versus fat storage
Amino Acid Sequence
Dosing
How muchdo I take?
Timing
Best time to take
Post-workout is ideal for training days—your muscles are like sponges ready to absorb nutrients. On rest days, morning with breakfast works well. Some users split doses between pre and post-workout.
With food?
Always have food available! IGF-1 LR3 can cause significant blood sugar drops. Eat a meal with protein and carbs within 30 minutes of injection. Never inject fasted unless you're very experienced.
If stacking
If stacking with growth hormone (HGH), inject IGF-1 LR3 at least 2-3 hours apart to avoid competition for receptors. Can be combined with MGF for potentially synergistic muscle-building effects.
Adjusting Your Dose
Increase if
+You've tolerated starting dose for 2+ weeks with no hypoglycemia issues
+Results have plateaued at current dose after 3-4 weeks
+Your training intensity has increased and you need more recovery support
+Blood sugar remains stable and you're eating consistently
Decrease if
-You experience shakiness, dizziness, or hypoglycemia symptoms
-Headaches persist beyond the first week
-Joint pain or water retention becomes uncomfortable
-Any side effect that concerns you—trust your body
Signs of right dose
✓Steady improvements in muscle fullness and recovery
✓Stable blood sugar with no hypoglycemic episodes
✓Improved workout performance and reduced soreness
✓No significant water retention or joint discomfort
Dosing Calculator
Calculate Your Exact Dose
Step 1: Peptide Weight
Find the weight printed on your peptide vial label
Look here!
The peptide weight is printed on the label
The weight is on the label
Select Weight
Look for a number followed by 'mg' on the vial label (e.g., 5mg, 10mg)
Suitability
Is thisright for me?
Best For
Serious Muscle Builders
If you're pushing hard in the gym and want to maximize every rep, IGF-1 LR3 helps your muscles grow through both hypertrophy (bigger cells) AND hyperplasia (more cells). That's a one-two punch that few other compounds offer.
Recovery-Focused Athletes
Train hard, recover faster. IGF-1 LR3 accelerates tissue repair and reduces the time you need between intense sessions. It's particularly valuable during high-volume training blocks or when preparing for competition.
Body Recomposition Goals
Looking to build muscle while losing fat? IGF-1 LR3 helps shuttle nutrients into muscle cells while improving how your body uses fat for fuel. Combined with proper diet, it supports that lean, muscular physique.
Post-Injury Rehabilitation
IGF-1 is your body's natural repair signal. The LR3 version stays active longer, potentially helping injured tissues heal more completely. Athletes recovering from muscle strains or tears may find it particularly beneficial.
Consider Alternatives If
Goal: Muscle growth with less hypoglycemia risk
Consider: MGF (Mechano Growth Factor), CJC-1295 + Ipamorelin, GHRP-2
Goal: General anti-aging and recovery
Consider: BPC-157, TB-500, GHK-Cu
Goal: Fat loss with muscle preservation
Consider: Tesamorelin, HGH Fragment 176-191, Ipamorelin
Who Should Avoid
Do not use if
×You have active cancer or a history of cancer—IGF-1 can stimulate cell growth including potentially cancerous cells
×You are pregnant or breastfeeding—effects on fetal/infant development are unknown
×You have diabetic retinopathy—IGF-1 may accelerate eye blood vessel growth
×You have uncontrolled diabetes—blood sugar management becomes extremely difficult
×You are under 21—can affect natural growth plate closure and hormonal development
×You've had allergic reactions to IGF-1 or similar peptides
Use with caution if
!You have any insulin resistance or pre-diabetes—monitor blood sugar very carefully
!You take medications that affect blood sugar levels—interactions can be dangerous
!You have heart conditions—IGF-1 can cause cardiac tissue growth
!You have kidney or liver issues—may affect peptide metabolism
!You have carpal tunnel syndrome—IGF-1 can worsen symptoms
!You have a family history of cancer—discuss with your doctor first
Not Sure?
Compare IGF-1 LR3 with similar peptides to find the best fit for your goals.
Administration
How do Iuse it?
Reconstitution
What you need
•Bacteriostatic water (BAC water)—the benzyl alcohol preservative keeps it sterile for multiple uses
•Insulin syringes (29-31 gauge)—1mL syringes with 100 unit markings work best
•Alcohol swabs for cleaning vial tops and injection sites
•Your IGF-1 LR3 powder vial (typically 1mg/1000mcg)
Example
If you have a 1mg (1000mcg) vial and add 2mL of BAC water, you get a concentration of 500mcg/mL. So every 0.1mL (10 units on an insulin syringe) equals 50mcg of IGF-1 LR3.
For a 50mcg dose at 500mcg/mL: draw 0.1mL (10 units). For 100mcg: draw 0.2mL (20 units). Always double-check your math—this peptide is potent!
Injection
Route
Subcutaneous injection (under the skin) is most common; intramuscular injection into specific muscles is also used for localized effects
Best sites
•Abdomen (2 inches from belly button)—most common for subcutaneous
•Target muscle (bicep, quad, etc.)—for site-specific enhancement
•Front or outer thigh—alternative subcutaneous site
•Upper arm fat pad—another subcutaneous option
Technique
1.Wash your hands thoroughly with soap and water
2.Clean the injection site with an alcohol swab, let it air dry completely
3.For subcutaneous: pinch about an inch of skin and insert at 45-90 degrees
4.For intramuscular: insert straight into the muscle belly at 90 degrees
5.Inject slowly and steadily—rushing can cause more discomfort
6.Wait 5-10 seconds before withdrawing the needle
7.Apply light pressure if needed, but don't rub the site
Storage
Before reconstitution
Keep your IGF-1 LR3 powder refrigerated at 36-46°F (2-8°C) for storage up to 1 month. For longer storage, freeze at -4°F (-20°C) or below. The powder is quite stable when kept cold and away from light.
After reconstitution
Once mixed with bacteriostatic water, refrigerate at 36-46°F (2-8°C). Never freeze the mixed solution—ice crystals will destroy the peptide structure. Keep away from light and use within 28-30 days.
Signs of degradation
Cloudy or hazy solution (should be crystal clear)
Visible particles floating or settled at bottom
Any color change—fresh solution is colorless
Unusual smell—properly reconstituted peptide has minimal odor
Sample Daily Schedule
Post-workout (within 30 minutes of finishing)
40-80 mcg depending on experience level injection
Site: Subcutaneous near abdomen or intramuscular into trained muscle
Training days: inject immediately after workout when muscles are primed for nutrient uptake. Have a protein and carb meal ready within 30 minutes to prevent hypoglycemia and maximize anabolic effect.
Morning with breakfast (rest days)
Same dose as training days injection
Site: Subcutaneous near abdomen
Rest days: inject with your morning meal. Continue cycles for 4-6 weeks, then take at least 4 weeks off to allow receptor sensitivity to reset. Some users do 5 days on, 2 days off.
Safety
Is itsafe?
Safety Profile
IGF-1 LR3 has been extensively studied in research settings and shows a predictable side effect profile when used responsibly. The primary concern is hypoglycemia, which is manageable with proper nutrition timing. Long-term safety data in humans is limited since it's used as a research compound. Joint discomfort and water retention are generally mild and resolve when cycling off.
Most safety data comes from animal studies and limited human research contexts. While these suggest a favorable profile at moderate doses, large-scale human clinical trials haven't been conducted. Always work with a healthcare provider familiar with peptide research when using any research compound.
Common Side Effects
Experienced by some users
Hypoglycemia (low blood sugar)
This is the most important side effect to understand. IGF-1 LR3 acts like insulin and drives glucose into cells, which can leave you feeling shaky, dizzy, or weak.
Management: Always eat within 30 minutes of injection. Keep fast-acting carbs (juice, glucose tablets) nearby. Learn your body's warning signs: shakiness, sweating, hunger, confusion.
Injection site reactions
Redness, slight swelling, or itching at the injection site is normal and usually fades within a day.
Management: Rotate injection sites regularly. Use proper sterile technique. A cool compress can help if irritation occurs.
Water retention
Some puffiness or bloating, especially in hands and face, as IGF-1 causes cells to hold more water.
Management: Usually mild and temporary. Moderate sodium intake, stay well-hydrated, and it typically resolves as your body adjusts or when you cycle off.
Headaches
Particularly common in the first week as your body adjusts to the peptide.
Management: Stay hydrated, don't skip meals, and the headaches usually subside after the first week. If persistent, consider reducing dose.
Less Common
•Joint pain or stiffness
•Numbness or tingling
These typically resolve with continued use or dose adjustment.
Stop and Seek Help If
×Any severe hypoglycemic episode that doesn't resolve quickly with food
×Persistent numbness, tingling, or carpal tunnel symptoms
×Joint pain that interferes with training or daily activities
×Signs of allergic reaction (rash, swelling, difficulty breathing)
×Any concerning or unusual symptoms that worry you
×Completion of your planned cycle (typically 4-6 weeks)
IGF-1 LR3 is a research compound, not approved for human therapeutic use by the FDA. This information is for educational purposes only and not medical advice. Always consult with a healthcare provider before starting, stopping, or modifying any research protocol.
Interactions
With other peptides
✓Potentially synergistic for muscle growth. MGF works locally while IGF-1 LR3 works systemically. Can be used together with careful timing.
✓Can be stacked for complementary effects—CJC increases natural GH release while IGF-1 LR3 provides direct IGF effects. Space injections apart.
✓Safe to combine. GHRP-6 stimulates hunger which can actually help prevent hypoglycemia from IGF-1 LR3.
!DANGEROUS combination. Both lower blood sugar dramatically. Severe hypoglycemia risk. Do NOT combine unless under strict medical supervision.
With medications
!Diabetes medications (Metformin, Sulfonylureas) - Increased hypoglycemia risk. Blood sugar-lowering effects compound dangerously. Requires medical supervision and dose adjustments.
!Insulin (medical) - Extremely dangerous combination. Both dramatically lower blood sugar. Can cause severe, life-threatening hypoglycemia.
✓Blood thinners (Warfarin, etc.) - May increase bruising at injection sites. Not dangerous but worth monitoring.
!Beta-blockers - Can mask hypoglycemia symptoms (shakiness, rapid heartbeat), making low blood sugar harder to detect. Use with caution.
With supplements
✓Creatine - Safe and potentially complementary. Both support muscle cell function and recovery.
✓Protein supplements - Highly recommended! Adequate protein maximizes IGF-1 LR3 benefits. Take protein with or shortly after injection.
✓Chromium - May enhance insulin sensitivity, potentially increasing hypoglycemia risk. Monitor blood sugar more carefully.
✓Alpha-Lipoic Acid (ALA) - Can increase glucose uptake, compounding hypoglycemia risk. Use lower doses of both if combining.
Effectiveness
Does itwork?
Evidence Level
Strong preclinical
What to Expect
Week 1
What you might notice
•Increased muscle fullness and pumps during workouts
•Possible hypoglycemia symptoms as you learn dosing/eating timing
•Mild headaches as your body adjusts
•Perhaps some water retention (slight puffiness)
•Improved workout recovery already beginning
What's normal
•Needing to eat more frequently to prevent low blood sugar
•Some initial side effects that should diminish
•Your muscles looking and feeling fuller
What's next
→Continue dialing in your nutrition timing
→Keep carbs accessible for hypoglycemia prevention
→Maintain consistent injection schedule
Week 2-3
•Noticeable improvements in workout recovery speed
•Muscle gains becoming more apparent
•Side effects typically stabilizing or diminishing
•Better nutrient partitioning—muscles look fuller, potentially leaner
•Improved strength and training capacity
•Settling into a routine with injection and eating timing
•Continued muscle fullness and improved pumps
•Energy levels stabilizing
→Maintain consistent protocol
→Consider slight dose adjustment if needed
→Continue tracking progress and any side effects
Week 4-6
•Peak effects—maximum muscle growth and recovery benefits
•Measurable gains in muscle size and strength
•Body composition improvements (more muscle, potentially less fat)
•Excellent workout recovery
•Possible receptor downregulation if extended beyond 6 weeks
•Best results typically seen during this period
•Stable side effect profile
•Feeling strong and recovered
→Complete cycle at 4-6 weeks
→Begin planning off-cycle period (4+ weeks)
→Maintain training intensity to preserve gains
Post-cycle (off period)
•Gradual return to baseline muscle fullness
•Maintained muscle gains if training and nutrition stay consistent
•No withdrawal effects—you simply stop
•Side effects resolve completely within days
•Slight reduction in muscle pump and fullness
•Return of normal blood sugar patterns
•Maintained strength and most muscle gains
→Continue solid training and nutrition
→Take at least 4 weeks off to reset receptors
→Plan next cycle if desired
Signs It's Working
Muscle Growth Indicators
✓Increased muscle fullness and pump during training
✓Visible improvements in muscle size within 2-3 weeks
✓Clothes fitting tighter in the chest, arms, and shoulders
✓Improved vascularity when lean
✓Strength gains in major lifts
Recovery Indicators
✓Less muscle soreness after intense training
✓Ability to train more frequently without overtraining
✓Faster return to peak performance between sessions
✓Reduced fatigue during high-volume training blocks
Body Composition Indicators
✓Improved muscle-to-fat ratio
✓More defined muscle separation
✓Better nutrient partitioning (muscles seem to absorb food better)
✓Maintained or reduced body fat despite calorie surplus
Not Seeing Results?
Common reasons
•Blood sugar management issues—if you're constantly hypoglycemic, you may not be eating enough around injections, limiting results
•Peptide degradation—improper storage is a common culprit; always check solution clarity and storage conditions
•Dose too low—starting doses are conservative; you may need to increase after assessing tolerance
•Poor quality product—only purchase from verified sources with third-party testing certificates (COAs)
•Insufficient training stimulus—IGF-1 LR3 enhances your body's response to training, but you still need to train hard
•Inadequate nutrition—not enough protein or calories limits the peptide's ability to build muscle
Key Research
[1]"Long R3 IGF-I differently affect development and messenger ribonucleic acid abundance for IGF-binding proteins and type I IGF receptors in bovine embryos"
Prelle K, Stojkovic M, et al., 2001
Finding: This foundational study demonstrated that LR3 IGF-I has dramatically reduced binding to IGF binding proteins compared to regular IGF-1, explaining why it remains active in the bloodstream much longer and has greater bioavailability for tissue effects.
[2]"Extracellular signal-regulated kinase and phosphoinositol-3 kinase mediate IGF-1 induced proliferation of fetal cardiomyocytes"
Sundgren NC, Giraud GD, et al., 2003
Finding: Researchers found that Long R3 IGF-I stimulates cell proliferation (hyperplasia) through both ERK and PI3K signaling pathways—this explains the unique ability of IGF-1 to create new cells, not just make existing cells bigger.
[3]"IGF-I and IGFBP-3 transport in the rat heart"
Boes M, Dake BL, et al., 2003
Finding: This study showed that LR3 IGF-I can bypass IGF binding proteins that normally sequester IGF-1, demonstrating why LR3 has greater bioactivity—it reaches target tissues more effectively than native IGF-1.
[4]"Inhibition of activin-like kinase 4/5 attenuates cancer cachexia associated muscle wasting"
Levolger S, Wiemer EAC, et al., 2019
Finding: LR3 IGF-I treatment effectively limited muscle mass loss in a cancer cachexia model, demonstrating its potent anti-catabolic effects and ability to preserve muscle tissue under conditions that normally cause severe muscle wasting.
[5]"Recombinant expression of IGF-1 and LR3 IGF-1 fused with xylanase in Pichia pastoris"
Lu Z, Liu N, et al., 2023
Finding: Purified LR3 IGF-1 displayed excellent bioactivity for cell proliferation comparable to standard IGF-1, confirming that the molecular modifications preserve its biological function while extending its active lifespan.
The Science
Stacking & Combinations
Frequently Asked Questions