Peptid-Klartext DE Community
Growth hormone

IGF-1 LR3: Effects, Evidence and Risks

Research use only: IGF-1 LR3 is not approved as a medicine. It is offered as a research substance labelled “for research purposes only – not for use in humans or animals”. This page summarises the state of research and is not a recommendation to use it.

Also known as Long R3 IGF-1, LR3-IGF-1, IGF-1 LR3.

StatusNot approved
EvidencePreclinical
Drug classSynthetic IGF-1 analogue (83 amino acids) · injection
Add as vial in tracker

We only show doses for approved medicines according to the prescribing information – in the calculator.

What is IGF-1 LR3?

IGF-1 LR3 is a modified form of the growth factor IGF-1 with one amino acid swapped and an extended end. It barely binds IGF-binding proteins and is therefore more potent and longer-acting than natural IGF-1.

How well studied is IGF-1 LR3?

There are no clinical studies in humans; the molecule was developed for laboratory and cell culture use. All claims about muscle growth rest on cell and animal data or anecdotes.

What side effects and risks does IGF-1 LR3 have?

IGF-1 acts like insulin: low blood sugar is the main acute risk, especially combined with other glucose-lowering agents. IGF-1 promotes cell growth – for the approved IGF-1 medicine an active tumour is a contraindication; for the more potent LR3 the risk is unknown. Grey-market products are untested (purity, sterility, content).

Is IGF-1 LR3 approved in Germany?

In short: no. Not approved for humans anywhere (only mecasermin is approved, for rare IGF-1 deficiency in children). Prohibited in sport (WADA S2, IGF-1 and analogues); may fall under the German AntiDopG. High counterfeit risk.

Sources

Note: We deliberately do not list any doses here. For approved medicines, your doctor sets the dose; for unapproved substances there is no reliable information.