Also known as Insulin-like growth factor 1 · Mecasermin · Increlex · Somatomedin C · rhIGF-1
The downstream effector of growth hormone — a 70-amino-acid recombinant protein, structurally a cousin of proinsulin, that carries out most of GH’s growth signal.
IGF-1 is the molecule that does much of growth hormone’s work. It is a 70-amino-acid single-chain protein (~7.6 kDa) with three disulfide bonds, structurally homologous to proinsulin — which is why insulin and IGF-1 signaling overlap. Produced mainly in the liver under GH stimulation, it is the mediator most responsible for GH’s anabolic and growth-promoting effects. The recombinant therapeutic version, mecasermin, is FDA-approved for severe IGF-1 deficiency. It pairs naturally with somatropin in this catalog: GH is the signal, IGF-1 is the message that actually reaches the tissues.
Where somatropin is the broadcast, IGF-1 is the signal received. Growth hormone acts on the liver and other tissues to induce IGF-1, and it is IGF-1 — acting through its own tyrosine-kinase receptor — that mediates most of the downstream growth and anabolic effects. Its structural kinship to proinsulin is not a coincidence: the IGF and insulin systems are evolutionary relatives, which is why IGF-1 has weak insulin-like (hypoglycemic) activity and why dosing is constrained by that overlap.
The therapeutic form, mecasermin (Increlex), is recombinant human IGF-1 approved in 2005 for children with severe primary IGF-1 deficiency or growth-hormone insensitivity — the Laron syndrome population, in whom GH itself does not work because the receptor or its signaling is broken. In those patients, supplying IGF-1 directly bypasses the failed step.
IGF-1 carries the same two layers of drama as growth hormone, sharpened. It is banned in sport and has been a recurring doping target; the most public episode was the 2013 "deer antler velvet spray" affair, in which an IGF-1-marketed product was tied to several athletes — a reminder that much of what is sold as IGF-1 outside medicine is unverified. And the longevity paradox is, if anything, cleaner here: low IGF-1 signaling is one of the most reproducible pro-longevity signals in biology, with IGF-1-pathway mutants living longer across species and Laron-syndrome individuals showing strikingly low cancer and diabetes incidence. A protein marketed for anti-aging sits on the very axis whose suppression extends life.
Binds the IGF-1 receptor (a tyrosine kinase) and, with lower affinity, the insulin receptor, activating PI3K/AKT and MAPK signaling to drive cell growth, proliferation, and survival. Circulating IGF-1 is largely bound to IGF-binding proteins, which modulate its availability.
Behind every vial of IGF-1 (Mecasermin) is the same exacting pipeline every research peptide runs — but the chemistry plays out differently for this molecule. Here is how IGF-1 (Mecasermin), specifically, is brought into being.
On paper, IGF-1 (Mecasermin) is C331H512N94O101S7 — about 7,649 daltons of precisely arranged atoms. Before a single bond is made, the target sequence, salt form, and purity threshold are written down as the contract the finished material must meet.
Assembling IGF-1 (Mecasermin) means roughly 70 coupling cycles on the synthesizer — one protected residue added at a time, which is also 70 chances for an incomplete coupling to seed a deletion impurity. At this length the growing chain is prone to aggregation on the resin, making every later cycle harder — long sequences are where small per-cycle losses compound into a messy crude. It also carries a disulfide bridge, an extra step beyond a plain chain that adds both capability and cost.
The crude mixture — IGF-1 (Mecasermin) plus its deletions and side products — is then separated on preparative HPLC, and where the cut is taken decides the difference between a genuinely pure peptide and a barely-passable one. IGF-1 (Mecasermin) carries 6 cysteines, whose thiols are oxidation-sensitive and can form disulfide links — reactive chemistry that purification has to control rather than ignore. It also contains oxidation-prone methionine or tryptophan residues, another family of impurities the chromatography has to resolve away.
A real batch of IGF-1 (Mecasermin) proves itself: identity confirmed by mass spectrometry against its ~7,649 Da, purity read directly off an analytical HPLC trace, water and counterion content measured. That batch-specific certificate of analysis is the only honest way to know what is actually in a vial of IGF-1 (Mecasermin) — and a short, cold, accountable chain of custody is how that purity survives the trip to your bench.
Recombinant IGF-1 is expressed (classically in E. coli), refolded to its native three-disulfide structure, and purified by chromatography. Release testing is protein-grade — peptide mapping, mass spectrometry, correct disulfide pairing, cell-based potency, host-cell-protein and endotoxin limits — not an HPLC purity figure alone.
Don't judge a vial by its cake. A fluffy, good-looking lyophilized powder reflects bulking agents and freeze-drying parameters — not purity. Insist on a batch-specific certificate of analysis.
Recent clinical trials and publications mentioning IGF-1, pulled automatically from ClinicalTrials.gov and PubMed and refreshed daily. Listings are unfiltered search results, not curated endorsements.
Insulin-like growth factor 1 — a 70-amino-acid protein, made mainly in the liver under growth-hormone stimulation, that carries out most of GH’s growth-promoting effects. The recombinant drug mecasermin (Increlex) is approved for severe IGF-1 deficiency.
GH stimulates the liver to produce IGF-1, and IGF-1 then does much of the actual signaling to tissues. That is why IGF-1 can treat people whose GH does not work (Laron syndrome).
IGF-1 is structurally homologous to proinsulin and binds the insulin receptor weakly, giving it mild insulin-like (glucose-lowering) effects.
No — this is a research and educational reference. Mecasermin is a prescription biologic; much of what is sold as IGF-1 outside medicine is unverified.
The active fragment of parathyroid hormone — a recombinant peptide that builds bone, exploiting a paradox: the same hormone resorbs bone when continuous, but builds it when pulsed.
ViewRecombinant 191-amino-acid human growth hormone — a folded protein biologic identical in sequence to pituitary GH, not a synthetic research peptide.
ViewModified GHRH(1-29) analog with short plasma half-life.
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