Side effects guide

IGF-1 LR3 Side Effects

IGF-1 analog / research chemical

IGF-1 LR3 has no human clinical trials, so its side-effect profile in people is uncharacterized. What can be stated comes from the biology of IGF-1 signaling rather than from studies of this analog in humans.[1][2]

Reviewed for accuracy · Last reviewed July 8, 2026

Reported side effects

COMMONHypoglycemia (IGF-1 lowers blood sugar) · Injection-site reactions
LESS COMMONTheoretical proliferative / cancer-growth concern from amplified IGF-1 signaling

IGF-1 lowers blood glucose, so hypoglycemia is a recognized risk of raising IGF-1 activity: symptoms can include shakiness, sweating, confusion, and in severe cases loss of consciousness. This is the most concrete near-term safety concern.

A second, more theoretical concern runs through all IGF-1 signaling. The IGF-1 receptor pathway has been reviewed as crucial for tumour transformation and the survival of malignant cells, so any agent that amplifies it raises a proliferative or cancer-growth concern. This is a concern about the pathway, not evidence that IGF-1 LR3 causes cancer in people, which has not been studied.

ImportantHuman safety of IGF-1 LR3 is uncharacterized. Because it can lower blood sugar, signs of hypoglycemia (shakiness, sweating, confusion) warrant urgent attention. Talk to a doctor before considering any use.

Managing side effects

Because human safety data is absent, there is no established management protocol. Anyone considering IGF-1 LR3 should understand that both the hypoglycemia risk and the theoretical proliferative concern are reasons the compound stays firmly in research-only territory.

FAQ

Is IGF-1 LR3 safe?Its safety in humans is uncharacterized because there are no human trials. Known concerns from IGF-1 biology include hypoglycemia and a theoretical cancer-signaling risk.
Why is there a cancer concern?The IGF-1 receptor pathway is reviewed as involved in the survival of malignant cells, so amplifying IGF-1 signaling carries a theoretical proliferative concern. It has not been studied specifically for IGF-1 LR3 in people.

References

  1. Role of insulin-like growth factor 1 receptor signalling in cancerBritish Journal of Cancer · 2007 · PMID 17393577 · PMC2361813 · DOI 10.1038/sj.bjc.6602627
  2. LONG R3 IGF-I Cell Culture Supplement (product and technical documentation)Repligen · current · Repligen product page, LONG R3 IGF-I
Reading up on research compounds? PepHub keeps your notes and sources in one place.Coming soon

This page is an independent educational reference and is not medical advice, and does not indicate any approval status for any use. IGF-1 LR3 is a research chemical with no human trials. Talk to a doctor before considering any compound.