IGF-1 LR3 Overview
A bodybuilding doctor's 12-minute overview of IGF-1 LR3: how he says it works, his dosing and injection views, the risks he stresses, and his tips for spotting fakes.
With Dr Todd Lee (MD)
Key moments
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- 0:04Where IGF-1 LR3 fitsLee introduces himself and places IGF-1 LR3 as its own category, separate from steroids, growth hormone and insulin.
- 1:08What the name meansHe breaks down IGF-1 LR3 as a modified long form of IGF-1 and says it makes insulin largely unnecessary.
- 1:38Modification and half-lifeLee says the added amino acids and the position three swap stretch the half-life from about 10 minutes to up to 12 hours.
- 2:41Where IGF-1 bindsHe says that at rest IGF-1 goes mostly to organs such as the intestines and spleen, while trained muscle is a more efficient target.
- 4:12Muscle and fat effectsLee lists protein synthesis, GLUT4 expression, nutrient uptake and fat loss as the effects he attributes to IGF-1.
- 6:15Injection site reasoningHe argues that injecting into the muscle you just trained makes more sense than injecting under the skin of the stomach.
- 7:17Dose and cycle lengthLee says he would keep doses under 50 micrograms a day to avoid receptor downregulation, and notes cycles are quoted from 21 to 50 days.
- 8:53Not for beginnersHe describes it as an advanced add-on that is a hassle to use and warns of possible permanent organ growth.
- 10:25Spotting fake productLee suggests checking for knuckle swelling, strong pumps and an HCG pregnancy test to judge what a vial really contains.
What the video says
Dr Todd Lee, who describes himself as a medical doctor and a 2012 IFBB North American lightweight bodybuilding champion, gives a solo overview of IGF-1 LR3 from a bodybuilder's perspective. He frames it as its own category of anabolic, separate from androgen receptor drugs, growth hormone and its secretagogues, and insulin. He argues it largely makes insulin unnecessary rather than replacing it.
Lee explains the name and the chemistry. According to him, LR3 is a synthetic version of IGF-1 with 13 amino acids added at the N terminal and an arginine swapped in at position three. He says this stretches the half-life from about 10 minutes for normal IGF-1 to up to 12 hours, and that research found it at least two times more effective. He then describes what IGF-1 does in muscle: he says it raises glucose uptake, mRNA production and protein synthesis, reduces protein breakdown, lowers body fat and increases GLUT4 expression. He adds that it binds best in trained, damaged muscle, while at rest it goes mostly to the intestines, spleen and possibly the heart. He also mentions beliefs about hair growth and testicle size, without vouching for them.
On use, Lee says dosing advice varies widely, from 10 micrograms to 120 micrograms a day, and cycles from 21 to 50 days. His own reasoning is to stay under 50 micrograms a day because he believes higher doses downregulate receptors, and to inject into the worked muscle rather than under the skin. He briefly describes reconstituting a 1 mg vial with 6% acetic acid, then stops short of more detail.
The last third is a caution. Lee calls it a poor value, a hassle to source, store and use, and an add-on for advanced users who have plateaued. He warns of possible permanent intestinal, spleen and heart growth. He closes with informal ways he suggests checking whether a product is real, including knuckle swelling, strong muscle pumps and a pregnancy test for HCG contamination, and says he is not approving use of the compound.
On each compound
IGF-1 LR30:04
Lee describes it as a long-acting modified IGF-1 that he says builds muscle, reduces fat and improves nutrient uptake. He recommends keeping doses under 50 micrograms a day and injecting into trained muscle, and stresses possible organ growth and sourcing problems. He says he does not approve its use.
See how your DNA reads IGF-1 LR3“I'm not giving any approval on the use of this compound”
What this video doesn’t settle
- Lee gives no studies or data for his claims on dosing, receptor downregulation or injection site, and says himself that there is not much data on the compound.
- The hair growth and testicle size claims are described as beliefs, and Lee suggests the testicle effect may come from HCG contamination.
- The fake-product tests (knuckle swelling, pumps, pregnancy test) are informal tips and cannot show purity or actual dose.
Questions this video answers
What is IGF-1 LR3 and how does it differ from normal IGF-1?
Lee says it is a synthetic IGF-1 with 13 amino acids added at the N terminal and arginine swapped in at position three. He says this raises the half-life from about 10 minutes to up to 12 hours.
What dose of IGF-1 LR3 does Dr Todd Lee talk about?
Lee says doses quoted online range from 10 to 120 micrograms a day, and cycles from 21 to 50 days. His own view is to stay under 50 micrograms a day because he believes higher doses cause receptor downregulation. He presents this as his reasoning, not as advice.
What side effects of IGF-1 LR3 does Lee warn about?
He warns that it can cause intestinal, spleen and heart growth, which he says can be permanent and produce an extended belly. He says injecting under the skin sends it to the organs, and that he thinks the compound is not worth it unless a user is meticulous.
How does Lee say you can tell if IGF-1 LR3 is fake?
He suggests that knuckle swelling points to growth hormone, and that very painful muscle pumps point to real IGF-1. He also says spraying some on a pregnancy test and getting a positive result suggests HCG. These are his informal checks, not lab testing.
Video by Mind And Muscle on YouTube, embedded as published. The summary is written by PeptidesDNA from the video; every claim in it is the speaker’s. Not affiliated with or endorsed by the creator. Not medical advice.
