Library / Growth hormone

Mecasermin

Also known as Increlex, Recombinant human IGF-1, rhIGF-1

Approved medicine

Recombinant human insulin-like growth factor 1. Approved only for children with severe primary IGF-1 deficiency or growth hormone gene deletion with neutralising antibodies.

Prescription medicine. Only a prescriber can decide whether a medicine suits you and at what dose. This page is information, not a recommendation.

Background

Mecasermin is recombinant human insulin-like growth factor 1 (IGF-1) made in bacteria. It was approved by the FDA in 2005 as Increlex, now marketed by Ipsen, for children who cannot make enough IGF-1 despite normal growth hormone.

How it is thought to work

It replaces IGF-1, the hormone that normally carries out most of growth hormone's effects on growing bones and tissues. Because IGF-1 also acts like insulin, it lowers blood sugar.

What is claimed, and the evidence

Claim	Evidence	Notes
Growth failure in children with severe primary IGF-1 deficiency or growth hormone gene deletion with neutralising antibodies	Approved use	Approved indication (TGA and FDA). Registry data show improved growth, with better responses when started young.
Muscle growth, fat loss, recovery or anti ageing in adults	No published evidence	No trials support these uses; the label says it is not a substitute for growth hormone and not for other forms of IGF-1 deficiency.

Side effects

Effect	How often	Notes
Low blood sugar (hypoglycaemia) Serious	Common	42 per cent of children in label trials had at least one episode; some had severe episodes and seizures or loss of consciousness.
Enlarged tonsils or adenoids, snoring, ear problems	Common	Tonsillar hypertrophy in 15 per cent; some needed surgery; otitis media and fluid in the middle ear reported.
Injection site lipohypertrophy and bruising	Common	Listed at 5 per cent or more in label trials.
Headache, dizziness, vomiting, joint pain	Common	Listed at 5 per cent or more in label trials.
Raised pressure inside the skull (intracranial hypertension) Serious	Uncommon	Occurred in three children in label trials; eye checks recommended.
Severe allergic reactions including anaphylaxis Serious	Rare	Label reports a low number of cases requiring hospital care.
Slipped hip growth plate and worsening scoliosis Serious	Uncommon	Label warnings for growing children.
Cancer (malignant neoplasia) Serious	Rare	Label reports several cases of cancer in treated children; contraindicated with active or past cancer.

Warnings

Can cause severe hypoglycaemia; the label says to give it shortly before or after a meal or snack.
The label reports cases of cancer in treated children and contraindicates it in anyone with active or past cancer.
Not for use in infants because of the benzyl alcohol preservative.
Unapproved products are not assessed by the TGA for quality, safety or efficacy and may be contaminated, non-sterile, underdosed, overdosed or contain a different substance altogether.

Regulatory status

Australia: Approved (ARTG, Increlex). Schedule 4.
United States: FDA approved (Increlex, 2005) for severe primary IGF-1 deficiency in children.

Sources

Also in Growth hormone

From the VialOwl library, reviewed 26 September 2026. For education and general information. It is not medical advice and not a recommendation to use Mecasermin.