IGF-1 LR3 calculator
A long-acting modified form of IGF-1 studied for anabolic effects. A research compound with no approved use and real hypoglycemia risk.
Also known as: Long R3 IGF-1, Insulin-like Growth Factor-1 Long R3
FDA status — not an approved drug Not FDA-approved for any use. IGF-1 LR3 is a research compound. Pharmaceutical IGF-1 (mecasermin) is a different, approved product for severe growth failure.
Schedule IGF-1 LR3 → Set your dosing schedule and get a phone notification when each dose is due. Free.
What IGF-1 LR3 is
IGF-1 LR3 is a modified, long-acting analog of insulin-like growth factor-1, the hormone that mediates many of growth hormone's effects. The LR3 modification extends its half-life and reduces binding-protein interference, making it more potent and longer-acting than natural IGF-1. It is a research compound with no approved use.
Research depth: 2/5 Preclinical anabolic data; no human trials of the LR3 analog and a real hypoglycemia risk. Human trials: None for the LR3 analog. This measures how much has been studied — counting animal and laboratory work — not whether it works for you.
How IGF-1 LR3 works
It activates the IGF-1 receptor, driving cell growth, proliferation, and nutrient uptake — particularly in muscle, which is its appeal. Because IGF-1 is structurally similar to insulin, it also activates glucose uptake and can cause hypoglycemia, an effect prolonged by the LR3 modification.
IGF-1 LR3 side effects
Commonly reported
- Hypoglycemia — shakiness, sweating, confusion
- Injection-site reactions
- Water retention
- Headache
Serious — seek medical care
- Hypoglycemia can be severe, especially without food
- IGF-1 promotes cell growth — a theoretical concern with any existing or undiagnosed cancer
- Prohibited in sport by WADA
This list is not exhaustive. Report anything unexpected to the clinician who prescribed it. If you have severe abdominal pain, trouble breathing, or signs of an allergic reaction, seek care the same day. See also our guide to peptide side effects by class.
A worked example
A 1 mg vial reconstituted with 2 mL of bacteriostatic water gives 0.5 mg/mL. A 50 mcg dose is then 0.1 mL — about 10 units on a 100-unit insulin syringe, giving roughly 20 doses per vial before accounting for residual volume left in the vial and syringe.
Prefer paper? Download the printable IGF-1 LR3 dosing chart (PDF) — every vial size and water volume in syringe units, with the same review byline as this page. All charts →
Commonly cited dose range
Figures circulating for IGF-1 LR3 run from 20 mcg to 100 mcg. Amounts discussed are in the tens of micrograms — much smaller than most peptides. Figures shown are community reference points. There is no established or approved dose, and the hypoglycemia risk is real.
Read this as reference information, not instruction. These numbers describe what is commonly discussed, not what is right for any individual. Dose, frequency, and whether to use IGF-1 LR3 at all are decisions for a licensed clinician who knows your history.
Common questions
Is IGF-1 LR3 the same as pharmaceutical IGF-1?
No. Mecasermin (Increlex) is approved recombinant IGF-1 for severe growth failure. IGF-1 LR3 is a modified, longer-acting research analog with no approved use.
What's the main risk of IGF-1 LR3?
Hypoglycemia. IGF-1 lowers blood sugar like insulin, and the long-acting LR3 form prolongs that effect. It also raises theoretical cancer concern because IGF-1 promotes cell growth.