What is IGF-1 LR3?
IGF-1 LR3 reconstitution is a small-numbers problem. The vials hold a fraction of what most peptide vials hold, so a mistake of a few units on the syringe is a large mistake in micrograms. This page lays out that math for the two common vial sizes.
IGF-1 LR3, also written Long R3 IGF-1, is a recombinant analog of human insulin-like growth factor 1 (IGF-1). The “R3” refers to an arginine that replaces the glutamic acid at position 3 of the natural sequence; “Long” refers to an extra peptide segment added to the start of the chain. Together these changes reduce binding to IGF binding proteins in laboratory systems. Long R3 IGF-1 is widely used as a supplement in cell-culture media, and it is also sold online in research-labeled vials. It is a different molecule from mecasermin, the approved recombinant human IGF-1 drug.
How much BAC water for an IGF-1 LR3 vial?
Because IGF-1 LR3 1mg and 0.1 mg vials are so small, the useful water volumes are small too. The chart below shows micrograms per U-100 unit for both sizes at volumes from half a millilitre upward.
| BAC water | 0.1 mg vial | 1 mg vial |
|---|---|---|
| 0.5 mL | 2 mcg/unit 0.2 mg/mL | 20 mcg/unit 2 mg/mL |
| 1 mL | 1 mcg/unit 0.1 mg/mL | 10 mcg/unit 1 mg/mL |
| 2 mL | 0.5 mcg/unit 0.05 mg/mL | 5 mcg/unit 0.5 mg/mL |
Each cell shows mcg per unit on a U-100 syringe (100 units = 1 mL) and the resulting concentration.
Notice how few micrograms each unit carries in the 0.1 mg column. At those levels, reading the syringe scale carefully matters more than it does for larger vials. The product labeling decides which volume applies. The BAC water to peptide ratio guide explains how vial size and water volume trade off.
IGF-1 LR3 1mg and 0.1 mg: worked examples
Three steps drive every result: concentration equals vial mg divided by water mL; volume equals the amount divided by concentration; units equal mL multiplied by 100. Here is an IGF-1 LR3 1mg vial, for example, if the amount you already have is written down in micrograms:
The math: 1 mg ÷ 1 mL = 1 mg/mL (1,000 mcg/mL), which is 10 mcg per unit. 50 mcg ÷ 1,000 mcg/mL = 0.05 mL = 5 units on a U-100 syringe.
And a 0.1 mg vial, where the same logic applies at a much lower concentration:
The math: 0.1 mg ÷ 1 mL = 0.1 mg/mL (100 mcg/mL), which is 1 mcg per unit. 20 mcg ÷ 100 mcg/mL = 0.2 mL = 20 units on a U-100 syringe.
Labels often mix units: a vial listed as 0.1 mg is the same as 100 mcg, because 1 mg = 1,000 mcg. Keep the vial and the amount in the same unit before you calculate; the mg to mcg conversion guide covers the switch.
IGF-1 LR3 calculator: what the numbers mean
This calculator converts an amount you already have, from product labeling, a document you are reviewing, or a qualified professional, into mL and U-100 syringe units. It does not suggest an amount, a frequency or a use, and it cannot tell you whether an amount is appropriate for anyone.
Enter the vial size exactly as printed, in mg or mcg, the water volume you are checking, and your amount. Because the numbers are small, check that the unit selector matches the label before reading the result. A vial entered as 1 mg when the label actually says 0.1 mg will make every figure on the screen far too high, and nothing in the result will look obviously wrong. Reading the label twice is the simplest check there is. Units are the same size on every U-100 syringe, whatever its capacity, as the U-100 syringe units to mL chart shows.
How to reconstitute IGF-1 LR3: what suppliers specify
IGF-1 LR3 is one of the compounds where supplier instructions differ most. Some cell-culture suppliers specify dissolving Long R3 IGF-1 in a dilute acid, such as dilute acetic acid or dilute hydrochloric acid, rather than water, and then diluting it further in a buffer or medium. Some research peptide sellers list bacteriostatic water instead. Some labels specify refrigeration or freezing after mixing, with their own time limits.
Whichever diluent a label specifies, the calculator math is unchanged: concentration depends on how much liquid goes in, not which liquid it is. How acid-based diluents compare with BAC water is covered in the guide to reconstitution solutions for peptides. The product labeling and a qualified professional decide the diluent, handling and administration.
IGF-1 LR3 regulatory status
IGF-1 LR3 is not an FDA-approved drug. It is sold as a laboratory reagent and in research-labeled vials, neither of which is the approved IGF-1 medicine. In sport, the World Anti-Doping Agency lists IGF-1 and its analogues among prohibited substances. There is no approved labeling for a research vial, so the amount printed on your own vial is the starting point for the math, and a correct calculation cannot confirm identity, purity or sterility.
IGF-1 LR3 FAQ
What is IGF-1 LR3?
IGF-1 LR3, or Long R3 IGF-1, is a recombinant analog of insulin-like growth factor 1 with an amino acid substitution and an extended chain. It is widely used in cell culture and sold in research-labeled vials.
How much BAC water goes in a 1 mg IGF-1 LR3 vial?
The calculator does not choose a volume. The chart shows micrograms per unit for several small water volumes; the product labeling decides the diluent and the volume.
Is 0.1 mg the same as 100 mcg?
Yes. 1 mg equals 1,000 mcg, so a 0.1 mg vial and a 100 mcg vial hold the same amount. Enter whichever unit the label uses and keep your amount in the same unit.
Why do some suppliers use acid instead of BAC water for IGF-1 LR3?
Some cell-culture suppliers specify a dilute acid for dissolving Long R3 IGF-1. Which diluent applies is a labeling question; the calculator math is the same either way.
Does this page give an IGF-1 LR3 dose?
No. It converts an amount you already have into mL and U-100 syringe units. It does not recommend an amount, a schedule or a use.