With insulin or other glucose-lowering medicines
Safety flag
Mecasermin has insulin-like effects and can add to medication-related hypoglycemia.
Interaction evidence source All research profiles
IGF-1 replacement
Mecasermin
Prepared by the ezGLP team. Sources last checked . Profile reviewed .
Also known as Recombinant human IGF-1, rhIGF-1
Routes represented in the knowledgebase: Subcutaneous (SubQ).
Educational overview
FDA-approved for severe primary IGF-1 deficiency in children, not for bodybuilding or general anti-aging use; can cause severe hypoglycemia.
Mecasermin is recombinant human insulin-like growth factor-1 (rhIGF-1), marketed as Increlex. Its labelled description gives a single 70-amino-acid chain with three intramolecular disulfide bridges, a sequence identical to endogenous human IGF-1, synthesised in genetically modified Escherichia coli. It is a hormone replacement rather than a secretagogue: instead of prompting the pituitary to release growth hormone, it supplies the downstream mediator directly, which is why it acts in children whose growth hormone receptors do not signal. Because IGF-1 is structurally related to insulin and activates overlapping receptors, the molecule also carries insulin-like effects on blood glucose.
The evidence base is a conventional regulatory development program rather than the thin literature typical of research peptides. Chernausek and colleagues reported long-term treatment with rhIGF-1 in the Journal of Clinical Endocrinology and Metabolism in 2007, following children with severe IGF-1 deficiency due to growth hormone insensitivity and documenting sustained increases in height velocity over years of treatment. The prescribing information summarises adverse reactions across those trials, most commonly hypoglycaemia, injection-site and systemic hypersensitivity reactions, and tonsillar or adenoidal hypertrophy. Later label revisions added observations of intracranial hypertension, slipped capital femoral epiphysis, scoliosis progression, and several cases of malignant neoplasia in treated children.
Mecasermin is a prescription biologic approved by the FDA for growth failure in paediatric patients two years and older with severe primary IGF-1 deficiency, or with growth hormone gene deletion who have developed neutralising antibodies to growth hormone. The label states it is not a substitute for growth hormone in approved growth hormone indications and not indicated for secondary IGF-1 deficiency such as malnutrition or hypothyroidism, and it contraindicates the product in closed epiphyses and malignant neoplasia. The European Medicines Agency granted a marketing authorisation on 3 August 2007 under exceptional circumstances. The World Anti-Doping Agency prohibits IGF-1 and its analogues at all times under the growth factors heading of section S2.
Increlex is supplied as a sterile aqueous solution in a multiple-dose glass vial preserved with benzyl alcohol, so unlike most peptides in this catalogue it requires no reconstitution. The label directs storage in a refrigerator at 2 to 8 degrees Celsius, protection from direct light, and no freezing, and it sets a 30-day in-use limit after the vial is first entered, with remaining material discarded. Those two dates are the ones an inventory record for mecasermin usually tracks, alongside lot number and expiry. The label also notes a mean terminal half-life of about 5.8 hours after subcutaneous administration in children with severe primary IGF-1 deficiency.
- Category
- IGF-1 replacement
- Routes represented
- Subcutaneous (SubQ)
- Storage context
- Follow the dispensed product or pharmacy label; storage and beyond-use time vary by formulation.
Published literature
No verified PubMed or DOI link is available for this entry.
Safety evidence
Common or reported: hypoglycemia, injection-site reactions, tonsillar enlargement, snoring, headache.
Serious or important: hypoglycemic seizure, intracranial hypertension, anaphylaxis, malignant-neoplasia warning.
Safety evidence sourceInteraction evidence
These are general, pairwise evidence notes. Green identifies the potential-synergy category, while Lv3/Lv2/Lv1 communicates evidence strength; it does not guarantee benefit or cancel a safety warning.
With Ipamorelin
Safety flag
Duplicate GH/IGF-axis stimulation may amplify IGF-1 elevation, edema, joint symptoms, and glucose intolerance.
Interaction evidence sourceCommon questions
Is mecasermin FDA approved?
Yes. Increlex (mecasermin) injection is FDA-approved for treating growth failure in paediatric patients two years of age and older with severe primary IGF-1 deficiency, or with growth hormone gene deletion who have developed neutralising antibodies to growth hormone. The label defines severe primary IGF-1 deficiency by height and basal IGF-1 standard deviation scores at or below minus three with normal or elevated growth hormone, and excludes secondary forms of IGF-1 deficiency.
What is the difference between mecasermin and growth hormone?
Somatropin is recombinant growth hormone, which acts on growth hormone receptors in the liver and other tissues and depends on that receptor pathway to generate IGF-1. Mecasermin is recombinant IGF-1 itself and bypasses the receptor entirely, which is why it is indicated where growth hormone signalling fails. The Increlex label states explicitly that the product is not a substitute for growth hormone in approved growth hormone indications.
Why does mecasermin cause hypoglycemia?
IGF-1 shares structural homology with insulin and activates overlapping receptor pathways, so mecasermin lowers blood glucose. The Increlex prescribing information warns that severe hypoglycaemia leading to hypoglycaemic seizures has been observed during treatment, describes the insulin-like hypoglycaemic effects as the reason the product is given close to a meal or snack, and lists hypoglycaemia among the most common adverse reactions recorded in its clinical trials.
Is mecasermin approved in Europe?
Yes. The European Commission granted a marketing authorisation valid throughout the European Union for Increlex on 3 August 2007. The authorisation was issued under exceptional circumstances, a route the European Medicines Agency uses when an applicant cannot provide comprehensive efficacy and safety data because the condition is too rare for a full dataset, and it carries continuing obligations to submit further information on the medicine.
Is IGF-1 banned in sport?
Yes. The World Anti-Doping Agency Prohibited List names insulin-like growth factor-1 and its analogues among the growth factors and growth factor modulators in section S2, prohibited at all times, in and out of competition. Mecasermin is rhIGF-1, so it falls squarely within that entry. An athlete with a diagnosed severe primary IGF-1 deficiency would need a therapeutic use exemption for the approved indication.
Further reading
- DailyMed, Increlex (mecasermin) injection prescribing information
- Chernausek et al., J Clin Endocrinol Metab 2007 (long-term rhIGF-1 in children with severe IGF-1 deficiency due to GH insensitivity)
- EMA, Increlex European public assessment report (authorised 3 August 2007 under exceptional circumstances)
- MedlinePlus, Mecasermin injection
- World Anti-Doping Agency, The Prohibited List (section S2, growth factors)
Summarised from published literature for reference only, with citations to the source. Evidence is graded as reported and is not a recommendation to combine, dose, or use any compound.
For personal tracking and education only. Not medical advice, diagnosis, or treatment, and not a medical device. Peptides may be prescription-only or unapproved where you live. Consult a licensed healthcare professional.