IGF-1 LR3
Growth factor (IGF)
Status & caution. Not FDA-approved and not on any compounding bulks list; sold strictly as a 'research chemical, not for human consumption.' Banned in tested sport (WADA). One of the higher-risk items here. It is a potent, long-acting growth factor: it can cause hypoglycaemia (insulin-like activity), and because IGF-1 drives cell proliferation broadly, it carries a real theoretical risk of promoting tumour growth and unwanted tissue/organ enlargement.
At a glance
Indications & what it's studied for
A standard cell-culture growth reagent in the lab. In physique/bodybuilding circles it is used — off-label and unapproved — to drive muscle hypertrophy and hyperplasia and recovery via the IGF-1 receptor and the PI3K/Akt and MAPK pathways.
Contraindications & cautions
Any active or prior cancer or elevated cancer risk (mitogenic signalling); active diabetic retinopathy; caution with anything that affects blood glucose. No human-use approval exists.
Commonly reported dosing
Reported, not recommended. The following describes what appears in research literature and community use. It is not a protocol, and unapproved peptides have no validated human dosing.
Community sources report small daily or every-other-day microgram doses in short cycles; this is unvalidated, and the hypoglycaemia risk makes measuring/reconstitution errors genuinely dangerous.
Routes of administration
Subcutaneous (sometimes intramuscular) injection.
Don't combine with
Insulin and other glucose-lowering agents (compounded hypoglycaemia risk); GH secretagogues and exogenous GH further raise IGF-1 signalling.
Reported to stack with
Often combined in community use with GH secretagogues or anabolic regimens — stacking growth signals multiplies both the proliferation and the metabolic risks.
Note: "stacking" combines multiple agents and multiplies unknowns; popularity of a combination is not evidence of its safety.
What the research actually shows
IGF-1 biology is well characterised and LR3 is a routine laboratory reagent, but there are essentially no controlled human-safety trials for the performance/physique use it is sold for.
Before acting on anything here, see Safety & the grey market and how to read a COA.