IGF-1 LR3
Also known as Long R3 IGF-1, Insulin-like growth factor 1 LR3
A long-acting IGF-1 analog used for muscle growth and recovery.
How it's taken (route)
a small shot into the fat just under the skin (belly, thigh, or love handle)
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- Documented dose
- 33–100 mcg
- Typical frequency
- Once daily, within 30 minutes after training
- Cycle
- 8 weeks on, 6 off
- Half-life
- About 20-30 hours
- Common vial sizes
- 1 mg
- Regulatory status
- Research chemical — not approved for human use.
Dose on a U-100 syringe (33–100 mcg)
| Vial | BAC water | Draw |
|---|---|---|
| 1 mg | 2.5 mL | 8.3–25 units |
| 1 mg | 3 mL | 9.9–30 units |
On a U-100 syringe, 100 units = 1 mL, and the syringe holds 100 units total. Most people keep a single subcutaneous injection under about 50 units — bigger volumes are usually mixed stronger (less water) or split into two shots. Only mixes that fit in one syringe are shown. Always double-check with the reconstitution calculator.
What it does
IGF-1 LR3 is the downstream signal growth hormone actually works through, delivered directly. People use it post-workout in 8-week blocks for muscle fullness, faster recovery between sessions, and better nutrient uptake into trained muscle.
Mechanism
Binds the IGF-1 receptor and drives protein synthesis and cell growth. The LR3 modification stops it being bound up by carrier proteins, so it stays active far longer than natural IGF-1.
Storage — lyophilisedwhat's this?
Refrigerate the sealed vial.
Storage — reconstitutedwhat's this?
Refrigerate and use within about 4 weeks.
Reconstitution noteswhat's this?
IGF-1 LR3 needs 0.6% acetic acid, not plain bacteriostatic water — plain water degrades it. Mix a 1 mg vial with 2.5 mL (250 units) of 0.6% acetic acid. 8 units is about 33 mcg, 13 units about 50 mcg, 25 units about 100 mcg. Ramp up over the first weeks and always dose after training with carbs and protein.
Stacks well with
- IpamorelinGH pulses upstream plus the growth signal they act through, delivered directly.
- BPC-157Added during injury recovery blocks for tendon and soft-tissue repair.
Popular combinations reported in the community and research literature — not a recommendation. Adding peptides multiplies side-effect risk; check with a clinician.
Commonly reported side effects
- Low blood sugar
- Hunger
- Tingling or numbness in hands
- Joint aches
- Fatigue
Contraindications noted
- Any active or prior cancer
- Uncontrolled diabetes
- Family history of hormone-sensitive tumours
Research notes
Strong anabolic signal, but IGF-1 promotes growth of all cells, which is the core long-term risk. Do not dose fasted or at bedtime.
Track this properly
Work out syringe units with the calculator, or set up a full schedule in about a minute.
Reference information only, not medical advice. See our medical disclaimer.