Does IGF-1 LR3 cause cancer?
Unknown. IGF-1 signalling drives cell growth, the approved parent is contraindicated in active neoplasia, and LR3 keeps more IGF-1 free and active for longer. That is a mechanistic caution, not a measured risk.
No human trial data
IGF-1 LR3 Side Effects
No human trial of LR3; the approved parent (mecasermin, rhIGF-1) has a label that defines the risks
IGF-1 LR3 is a longer-acting, more potent analogue of IGF-1 with no human trials. The approved parent molecule, mecasermin, has a label whose leading adverse effect is hypoglycaemia, followed by tonsillar hypertrophy, intracranial hypertension and, in children, slipped capital femoral epiphysis. LR3's reduced binding to IGF-binding proteins means more free IGF-1 — so the hypoglycaemia signal, if anything, is the one to expect.
Research-use information only. Research-grade IGF-1 LR3 is not an approved medicine; where trial or label figures appear below they belong to the pharmaceutical product studied, not to any research vial. This page does not give dosing or medical advice.
What is reported
Every rate carries its source. Where no source exists, no rate is printed.
| Effect | Rate (sourced) | Detail | Source |
|---|---|---|---|
| Hypoglycaemia (parent molecule) | not quantified | The most common adverse reaction on the mecasermin label; dose-dependent. | Increlex (mecasermin) prescribing information |
| Tonsillar hypertrophy, intracranial hypertension, lymphoid tissue growth (parent) | not quantified | Reported in paediatric use. | Increlex label |
What is not known
- •Any human data on LR3 itself.
- •Cancer-related risk of sustained free IGF-1 — theoretical, unstudied for LR3.
Mechanism-based cautions
- •IGF-1 is mitogenic; the parent label contraindicates active or suspected neoplasia.
- •Hypoglycaemia risk is amplified by the analogue's longer action and by fasting.
Regulatory status: Not approved anywhere. Mecasermin (the parent) is approved for severe primary IGF-1 deficiency in children.
References
- Ipsen Increlex (mecasermin) prescribing information. FDA label, 2019.
What is actually in a research vial
Everything above describes IGF-1 LR3 the molecule. The risk specific to a research vial is different: it may not contain IGF-1 LR3 at the labelled amount, and it may contain what the synthesis left behind. Identity (mass spectrometry), purity (HPLC), measured net content and an endotoxin result are the four lines on a certificate that bear on adverse effects, and only a certificate you can check at the laboratory tells you any of them. This is what we have verified for IGF-1 LR3 so far.
IGF-1 LR3 certificates we have opened
1 certificate for IGF-1 LR3 in the COA library: 0 checkable on the laboratory's own site, 1 stating measured mass against the label, 1 carrying a flag.
- Rivn Peptides· 1mg · lot IGF-217 · Freedom Diagnostics Search Code RIVN2606290308· 99.76% purity· 119% of label· vendor-hosted onlyOver label (>115%)One vial measured