Mecasermin (Increlex)
Recombinant human IGF-1, given twice daily with a meal. For children with severe primary IGF-1 deficiency.
Checked 2026-10-22 against the US label Researched and written by Kymata Health Editorial Report an error
- Sold as
- Increlex
- Full name
- mecasermin
- Maker
- Eton Pharmaceuticals (formerly Ipsen)
- Status
- Prescription only; US label since 2005
- Sport
- WADA S2, prohibited at all times
What is mecasermin?
Short answer
Mecasermin is recombinant human IGF-1, the hormone GH normally makes the liver release. It is for children whose bodies make enough GH but cannot turn it into IGF-1 (severe primary IGF-1 deficiency). Eton Pharmaceuticals sells it as Increlex; the label says it is not a substitute for GH.
How it works
Mecasermin acts on the IGF-1 receptor directly, downstream of GH. Because IGF-1 also lowers blood sugar the way insulin does, each dose is given within 20 minutes of a meal or snack. Its half-life in children with severe primary IGF-1 deficiency is 5.8 hours, with a peak about 2 hours after injection. (Increlex label)
Who is Increlex approved for?
The US label's indications, in its own terms.
US label indications
2- Children 2 years and older with severe primary IGF-1 deficiency: height SDS ≤ −3.0, basal IGF-1 SDS ≤ −3.0, and normal or high GH
- Children with GH gene deletion who have developed neutralizing antibodies to GH
What dose does the Increlex label give?
What the label states, for the patients it covers. Not a dose for anyone reading this: the prescriber sets it.
On the label
| Label wording, summarised | Source |
|---|---|
| Starts at 0.04 to 0.08 mg/kg twice daily under the skin, raised by 0.04 mg/kg per dose if tolerated for a week; label maximum 0.12 mg/kg twice daily; within 20 minutes of a meal or snack. | (Increlex label) |
How long does mecasermin last, and when is IGF-1 checked?
Pharmacokinetics
| Measure | Label value | Source |
|---|---|---|
| Half-life (children) | 5.8 h | (Increlex label) |
| Time to peak | About 2 h | (Increlex label) |
What are the warnings for Increlex?
From the current US label. A clinician weighs them for each patient.
Status Prescription only. Increlex has had a US label since 2005 (Eton Pharmaceuticals (formerly Ipsen)). WADA prohibits it at all times (S2). (Increlex label; WADA Prohibited List 2026)
Warnings specific to this drug
| Warning | Source |
|---|---|
| Hypoglycemia: given within 20 minutes of a meal or snack; the label advises avoiding high-risk activities such as driving or exercise for 2 to 3 hours after a dose. | (Increlex label) |
| Intracranial hypertension with papilledema, visual changes, headache, nausea or vomiting; eye exams at the start and during treatment. | (Increlex label) |
| Malignancy: contraindicated with cancer or a history of it. Tumours were seen more often at higher than recommended doses or with IGF-1 above the normal range; stop if a malignant tumour develops. The current label has no boxed warning. | (Increlex label) |
| Lymphoid tissue (tonsil, adenoid) enlargement; the benzyl alcohol preservative means use in infants is not recommended. | (Increlex label) |
Frequently asked questions
Questions
- Is mecasermin the same as IGF-1 LR3?
- No. Mecasermin is recombinant human IGF-1, the natural sequence, with a US label. IGF-1 LR3 is a modified research compound with an extended sequence and no human trials.
- Why is Increlex given with food?
- IGF-1 lowers blood sugar the way insulin does. The label times each dose within 20 minutes of a meal or snack to prevent hypoglycemia.
- Does Increlex have a boxed warning?
- Not on the current US label. Cancer is a contraindication and a numbered warning: tumours appeared more often at high doses or high IGF-1 levels.
- Is mecasermin banned in sport?
- Yes. WADA lists IGF-1 and its analogues, including mecasermin, under S2, prohibited at all times.
The growth hormone family
GH itself, the drugs that make the pituitary release more of it, and IGF-1 downstream. Half-lives are human values.
Three ways to raise GH
| Class | Acts on |
|---|---|
| GHRH analog | GHRH receptor on the pituitary (cAMP) |
| Ghrelin-receptor agonist | Ghrelin receptor (GHS-R1a) in hypothalamus and pituitary |
| Growth hormone (daily) | GH receptor directly; bypasses the pituitary |
| Growth hormone (weekly) | GH receptor directly, released over a week |
| IGF-1 (this page) | IGF-1 receptor, downstream of GH |
Compared
16 agents| Agent | Class | Labelled product | Half-life (human) | Taken |
|---|---|---|---|---|
| Somatropin (rhGH) | Growth hormone (daily) | Genotropin, Humatrope, Norditropin, Omnitrope, Zomacton, Serostim | 2 to 3.8 h (SC, across labels) (Humatrope label) | Daily injection (label) |
| Somapacitan | Growth hormone (weekly) | Sogroya | about 2 to 3 days (adults) (Sogroya label) | Weekly injection (label) |
| Somatrogon | Growth hormone (weekly) | Ngenla | 37.7 h (effective, children) (Ngenla label) | Weekly injection (label) |
| Lonapegsomatropin | Growth hormone (weekly) | Skytrofa | about 31 h (prodrug, children) (Skytrofa label) | Weekly injection (label) |
| Tesamorelin | GHRH analog | Egrifta SV, Egrifta WR | 8 to 38 min (by formulation and study) (Egrifta WR label) | Daily injection (label) |
| Sermorelin | GHRH analog | None | 6 to 7 min IV (EU product information) (Geref 50 SPC (HPRA)) | Daily injection in studies |
| CJC-1295 with DAC | GHRH analog | None | 5.8 to 8.1 days (Teichman 2006, JCEM) | Weekly or every other week in studies |
| CJC-1295 without DAC (mod GRF 1-29) | GHRH analog | None | No human value published | No human study published |
| Ipamorelin | Ghrelin-receptor agonist | None | 2 h (IV infusion) (Gobburu 1999, Pharm Res) | Single IV infusions in the human study |
| GHRP-2 | Ghrelin-receptor agonist | None | No human value published | IV test doses in studies |
| GHRP-6 | Ghrelin-receptor agonist | None | 2.5 h (IV) (Cabrales 2013, Eur J Pharm Sci) | IV test doses in studies |
| Hexarelin | Ghrelin-receptor agonist | None | No human value published | IV test doses in studies |
| MK-677 (ibutamoren) | Ghrelin-receptor agonist | None | No human value published | Daily by mouth in studies; GH raised over 24 h |
| Macimorelin | Ghrelin-receptor agonist | Macrilen | 4.1 h (Macrilen label) | One oral dose, as a diagnostic test (label) |
| Mecasermin (rhIGF-1) | IGF-1 | Increlex | 5.8 h (children) (Increlex label) | Twice daily with a meal (label) |
| IGF-1 LR3 | IGF-1 | None | No human value published | No human study published |
GH axis guides3
- Growth hormone: the GH axisHow GH is controlled, every agent compared
- GH pulse simulatorDose times against the natural sleep and exercise GH pulses, modelled from half-lives
- IGF-1 monitoring on GH-axis treatmentWhy IGF-1 is the test, when to draw it on weekly GH, and what the labels say to do with it.