IGF-1 LR3 dosing protocol
IGF-1 LR3 dosing in micrograms — conservative, standard, and aggressive protocols, pre vs post-workout timing, reconstitution math, and cycle length.
Updated May 7, 2026 · 4 min read
IGF-1 LR3 dosing sits in a different magnitude band than every other peptide on this site. Doses are in micrograms, not milligrams. The typical daily total is 20–50 mcg, the cycle is short (4–6 weeks), and the side-effect profile gets steeper fast above 80 mcg/day. This guide covers the three reported community protocols, the timing logic, and the reconstitution math that makes the small draws workable.
The three reported protocols
| Tier | Daily total | Per-injection | Cadence |
|---|---|---|---|
| Conservative | 20 mcg | 20 mcg once | Once daily, post-workout |
| Standard | 40 mcg | 20 mcg | Twice daily, pre + post |
| Aggressive | 60–80 mcg | 30–40 mcg | Twice daily |
Above 80 mcg/day, hypoglycemia, hand numbness, and headache intensity climb without a proportional jump in anabolic effect. Most experienced users cap their cycles around 60 mcg/day for that reason.
Pre-workout vs post-workout
IGF-1 LR3 has a 20–30 hour half-life. That means the peak vs trough conversation matters less than for short-acting peptides — once you've been dosing for a few days, your circulating IGF-1 LR3 is relatively flat. Timing arguments are about acute receptor saturation at the working tissue, not about half-life.
- Pre-workout (30–60 min before): floods the IGF-1 receptor at the working muscle during training. Hypoglycemia risk is highest here — eat a carb-containing meal first.
- Post-workout (within 30 min): pairs IGF-1 receptor activation with the post-training nutrient window. Lower hypoglycemia risk if you eat right after.
- Split (pre + post): smooths exposure on training days. Standard for the 40 mcg/day protocol.
On rest days, most users dose once in the morning with a meal.
Reconstitution math
IGF-1 LR3 ships in 1 mg vials almost exclusively. Standard mix:
1 mg vial + 1 mL bacteriostatic water = 1000 mcg/mL.
A 20 mcg dose = 0.02 mL = 2 units on a U-100 insulin syringe.
A 40 mcg dose = 0.04 mL = 4 units.
A 30 mcg dose = 0.03 mL = 3 units.
Two units on a 30-unit insulin pin is a tiny draw. Many users dilute further to make the math more forgiving — 1 mg + 2 mL water gives 500 mcg/mL, so a 20 mcg dose becomes 4 units instead of 2. The trade-off: more BAC water means slightly faster degradation of the reconstituted peptide. See storage.
The reconstitution calculator handles either approach.
Body-weight scaling
Body-weight scaling for IGF-1 LR3 is weak. The IGF-1 receptor saturates at relatively low circulating concentrations, so a 250 lb user does not need triple the dose of a 150 lb user. Most reported protocols use a flat dose range and adjust by tolerance, not by mass.
A reasonable starting frame:
| User profile | Starting dose |
|---|---|
| First IGF-1 LR3 cycle, any size | 20 mcg/day for week 1 |
| Tolerated week 1, ready to titrate | 30–40 mcg/day |
| Experienced, prior clean cycles | 40–60 mcg/day |
Cycle length
Standard reported cycles run 4–6 weeks. Beyond 6 weeks, two issues compound:
- Receptor desensitization — sustained supraphysiologic IGF-1 receptor activation downregulates receptor expression. The marginal benefit per mcg drops.
- Cancer-axis caveats — IGF-1 elevation is implicated in cellular proliferation pathways. Longer cycles mean longer exposure to elevated IGF-1, which is the variable the epidemiology cares about.
Off-period: 4–8 weeks minimum between cycles. Year-over-year cumulative cycle weeks matter more than any single cycle. See cycle length.
Injection technique
Subcutaneous injection in abdomen, thigh, or upper arm. The very small volumes mean technique is forgiving — the draw is more important than the depth. See injection sites.
A 30-gauge, 5/16-inch insulin pin is standard. Rotate sites every injection.
Common protocol mistakes
- Confusing mcg and mg. A 1 mg dose is 1000 mcg — fifty times a typical IGF-1 LR3 dose. This mistake is severe. Doses are in micrograms.
- Dosing pre-workout on an empty stomach. Hypoglycemia risk is real. Eat first.
- Stacking with insulin in the first cycle. Advanced protocol, serious risk. Not for beginners.
- Running 8+ week cycles to "see if it works." If 4–6 weeks didn't produce signal, more weeks won't.
- Skipping baseline labs. Fasting glucose, A1C, and ideally an IGF-1 baseline are worth running before cycle one.
Contraindications
- Active or recent cancer diagnosis
- Strong family history of hormone-sensitive cancer (breast, prostate, colorectal)
- Type 1 diabetes or pre-diabetic with poor glucose control
- Pregnancy or lactation
- Untreated retinopathy