Mecasermin: research

Prescription IGF-1 approved for rare childhood growth failure; low blood sugar is a major risk.

Also called: Increlex, rhIGF-1, Recombinant human IGF-I, Somatomedin C.

IGF-1 and analogues · Recombinant human IGF-1 replacement · Evidence: Approved drug.

At least 106 human research reports were found, including case reports and studies that reuse participants. These are not 106 separate trials.

Studies

FDA pooled growth studies. open-label, n=71, Children with severe primary IGF-1 deficiency. Growth increased in a rare pediatric population; most studies lacked a control group. (source)
Early European replacement study. open-label, n=27, 27 patients with GH receptor deficiency. Early replacement studies showed growth and glucose effects. (source)
Laron syndrome over three years. open-label, n=9, Prepubertal children with Laron syndrome. Once-daily native IGF-1 improved growth in a small early cohort. (source)
Ecuador placebo-controlled growth trial. rct, n=17, Prepubertal children with GH receptor deficiency. Controlled evidence supports growth effects in GH receptor deficiency. (source)
80 versus 120 mcg/kg. open-label, n=22, Children with GH receptor deficiency. The higher dose did not improve measured growth in this small comparison. (source)
European long-term growth. open-label, n=33, Laron syndrome or GH-gene deletion. Growth gains persisted, but most patients remained very short. (source)
US long-term growth cohort. open-label, n=76, Children with severe IGF-I deficiency due to GH insensitivity. Replacement increased growth, with frequent adverse effects. (source)
Adult height after long-term therapy. cohort, n=21, Severe IGF-I deficiency treated from childhood. Childhood treatment improved final height estimates. (source)
MS301 dose-finding study. rct, n=136, Short prepubertal children with low IGF-I and normal stimulated GH. Growth response increased with dose in children with low IGF-I. (source)
Growth hormone plus IGF-1. rct, GH-sufficient short children with low IGF-1. The highest combination arm grew faster than GH alone. (source)
European registry growth response. cohort, n=242, 242 children/adolescents receiving rhIGF-1. Real-world growth responses varied and were better at younger ages. (source)
Registry low-blood-sugar risk. cohort, n=306, Children/adolescents in the Eu-IGFD registry. Low blood sugar is a continuing risk, especially with a prior history. (source)
Near-adult height registry analysis. cohort, n=102, Registry participants reaching near-adult height. Final height improved, particularly when treatment began before puberty. (source)
ALS North America trial. rct, n=266, Adults with sporadic ALS. An initial positive ALS result was not reproduced by the later large trial. (source)
ALS European trial. rct, n=183, Adults with ALS. This European ALS trial did not show benefit. (source)
ALS two-year trial. rct, n=330, Adults with ALS. The larger confirmatory ALS trial found no benefit. (source)
Cochrane ALS review. meta-analysis, n=779, Three randomized trials in adults with ALS. Inconsistent, low-quality evidence did not establish ALS benefit. (source)
Rett phase 1 and extension. open-label, n=12, 12 girls with MECP2 mutations; 9 had Rett syndrome. A small safety study generated signals later tested in a controlled trial. (source)
Italian Rett cohort. cohort, n=20, 10 treated and 10 matched untreated girls with Rett syndrome. An unblinded cohort suggested improvement on selected ratings. (source)
Rett placebo crossover trial. crossover-rct, n=30, Girls with classic Rett syndrome after regression. The controlled Rett trial did not reproduce an overall benefit. (source)
Rett systematic review. systematic-review, Clinical mecasermin studies in Rett syndrome. Larger controlled studies are still needed for Rett syndrome. (source)
Phelan-McDermid pilot. crossover-rct, n=9, Children with Phelan-McDermid syndrome, ages 5–15. A tiny pilot reported signals needing replication. (source)
Phelan-McDermid follow-up. crossover-rct, n=10, Children with Phelan-McDermid syndrome, ages 5–9. The follow-up did not confirm benefit on its primary endpoint. (source)
Type 1 diabetes dose-finding. rct, n=223, People with type 1 diabetes, ages 11–66; all continued insulin. Glycemic improvement came with dose-related safety concerns. (source)
Retinal safety in younger patients. cohort, Age 11–21 subset of the 223-person type 1 diabetes trial. Higher doses carried retinal and fluid-retention signals. (source)
Adolescent type 1 diabetes trial. rct, n=53, Adolescents and young adults on multiple daily insulin injections. Low once-daily doses gave a temporary glycemic signal. (source)
Type 2 diabetes metabolic study. single-arm, n=8, Adults with poorly controlled type 2 diabetes. Short exposure changed glucose handling, not long-term diabetes outcomes. (source)
Severe insulin resistance pilot. single-arm, n=6, Six patients with severe insulin resistance, without insulin-receptor mutations. A small pilot supports specialist interest in rare insulin-resistance syndromes. (source)
Long-term insulin receptor disorders. case-series, n=4, Four males with Donohue or Rabson-Mendenhall syndrome. High doses did not prevent long-term metabolic deterioration. (source)
Duchenne muscle-function trial. rct, n=38, Prepubertal ambulatory boys with Duchenne dystrophy on steroids. Growth improved, but walking and motor function did not. (source)
Bone density with IGF-1 and estrogen. rct, n=60, Adult women with anorexia nervosa and low bone density. A small study found a bone-density signal with combined therapy. (source)
IGF-1 followed by risedronate. rct, n=90, Women with anorexia nervosa and low bone density. Sequential therapy produced a modest spine-density signal. (source)
Estradiol with or without IGF-1. rct, n=75, Women ages 14–22 with anorexia nervosa. Adding IGF-1 did not improve bone outcomes in this study. (source)
PAPP-A2 deficiency and PK. pk-study, n=7, Three affected siblings, two carrier parents and two healthy controls. PK and rare-disease responses did not remove the risk of raised brain pressure. (source)
HIV lipodystrophy pilot. single-arm, HIV patients with lipoatrophy and insulin resistance. A small uncontrolled study did not reverse loss of subcutaneous fat. (source)
Painful small-fiber neuropathy. rct, n=40, Adults with idiopathic painful small-fiber-predominant neuropathy. This controlled neuropathy trial found no symptom benefit. (source)
Acute kidney injury trial. rct, n=72, Hospitalized adults with acute renal failure and major illness. Human kidney recovery did not reproduce the animal benefit. (source)
Delayed transplant function. rct, n=43, Recipients of deceased-donor kidney transplants. Immediate dosing did not improve transplant kidney function. (source)
Multiple sclerosis pilot. open-label, n=7, Patients with multiple sclerosis. The small pilot found no MRI or clinical benefit. (source)
Retinal and skin permeability. crossover-rct, n=8, Healthy adults. Native IGF-I can alter skin and retinal vessel permeability. (source)
Native IGF-I pharmacokinetics. pk-study, Healthy volunteers and patients with GH receptor deficiency. The same native hormone has different clearance in different populations. (source)
Anaphylaxis case report. case-report, n=1, A 13-year-old boy receiving mecasermin. Severe allergic reactions can occur. (source)
MS306 growth extension. open-label, n=114, Children previously in MS301. Status: terminated. See posted results and limitations. (source)
MS302 once-daily growth study. single-arm, n=45, Short children with low IGF-1. Status: completed. See posted results and limitations. (source)
Anorexia short-term safety. single-arm, n=16, Adolescent girls with anorexia nervosa. Status: completed. See posted results and limitations. (source)
X-linked SCID growth study. single-arm, n=6, Boys with X-linked severe combined immunodeficiency and growth failure. Status: terminated. See posted results and limitations. (source)
Anorexia six-month bone study. single-arm, n=28, Females ages 12–26 with anorexia nervosa. Status: completed. See posted results and limitations. (source)
Single-dose muscle glucose study. crossover-rct, n=8, Adults undergoing muscle microdialysis. Status: completed. See posted results and limitations. (source)
Ehlers-Danlos tendon study. rct, n=15, Ehlers-Danlos patients and healthy controls. Status: completed. See posted results and limitations. (source)
Cystic fibrosis growth study. rct, n=15, Patients with cystic fibrosis. Status: terminated. See posted results and limitations. (source)
Heart-attack pilot. rct, n=47, Adults after a heart attack. Status: completed. See posted results and limitations. (source)
Crohn disease growth study. single-arm, n=3, Children with Crohn disease. Status: terminated. See posted results and limitations. (source)
Autism pilot with posted results. crossover-rct, n=3, Children with autism spectrum disorder. Status: terminated. See posted results and limitations. (source)
GH deficiency and diabetes pilot. rct, n=14, Adults with GH deficiency and diabetes or impaired glucose tolerance. Status: completed. See posted results and limitations. (source)
US long-term patient registry. cohort, n=1378, Patients prescribed mecasermin. Status: terminated. See posted results and limitations. (source)

Mecasermin dosage

Typical reported dose: 0.04 mg per kg twice a day to start, up to 0.12 mg per kg

US label, 0.04 mg/kg start: 0.04 mg/kg per dose twice daily for at least 1 week, then If tolerated, 0.08 mg/kg per dose twice daily for at least 1 week, then If tolerated, up to 0.12 mg/kg per dose twice daily twice daily, under the skin. Drug label. Studied in: FDA-labelled pediatric growth-failure indications, age 2 and older. (source)
US label, 0.08 mg/kg start: 0.08 mg/kg per dose twice daily for at least 1 week, then If tolerated, up to 0.12 mg/kg per dose twice daily twice daily, under the skin. Drug label. Studied in: FDA-labelled pediatric growth-failure indications, age 2 and older. (source)
EU label, 0.04 mg/kg start: 0.04 mg/kg per dose twice daily for at least 1 week, then If no significant adverse reactions, 0.08 mg/kg twice daily, then If tolerated after at least another week, maximum 0.12 mg/kg twice daily twice daily, under the skin. Drug label. Studied in: Children/adolescents ages 2–18 with severe primary IGF-1 deficiency. (source)
Clinician-published cautious start: 0.04 mg/kg per dose twice daily in younger or hypoglycemia-prone children, then Increase more slowly as tolerated toward 0.1–0.12 mg/kg per dose twice daily; no fixed weekly schedule twice daily, under the skin. Clinician-published. Studied in: Children with confirmed severe primary IGF-1 deficiency. (source)
Growth study, 80 mcg/kg: 80 mcg/kg per dose, twice daily twice daily, under the skin. Studied in a trial. Studied in: Children with GH receptor deficiency. (source)
Growth study, 120 mcg/kg: 120 mcg/kg per dose, twice daily twice daily, under the skin. Studied in a trial. Studied in: Children with GH receptor deficiency. (source)

These are doses reported in labels, trials or user reports, not a personal plan. Check the source behind each one.

Work out syringe units with the dosing calculator

Mecasermin side effects and risks

Reported side effects

Low blood sugar: FDA pool: 30/71, 42%; 5 had severe episodes and 4 had seizures or loss of consciousness., serious. Link doses to food and monitor glucose. Lower the dose if episodes occur despite adequate food. (source)
Tonsil or adenoid growth: FDA pool: tonsillar growth in 11/71, 15%; 7 required surgery., moderate. Assess new snoring, sleep pauses, swallowing problems or ear symptoms. (source)
Injection-site fat growth: 32% in the separate 76 patient long term cohort; not the FDA 71 patient pool., mild. Rotate injection sites. (source)
Headache or vomiting: Each reported in ≥5% in the FDA pool; exact separate rates are not given there., moderate. Persistent severe headache, vomiting or visual changes need urgent assessment. (source)
Raised pressure around the brain: FDA pool: 3/71 had intracranial hypertension., serious. Eye examination at baseline and periodically; assess new headaches or vision changes. (source)
Severe allergic reaction: Postmarketing anaphylaxis estimate 0.3%; voluntary reports have uncertain denominators., serious. Stop and seek emergency care for breathing trouble or facial swelling. (source)
Joint pain, bruising or ear problems: Individual listed reactions occurred in ≥5% in the FDA pool; precise rates not supplied., moderate (source)
Edema and jaw pain: Higher dose type 1 diabetes arms had unacceptable rates; exact rates not extracted., moderate (source)
Worsening diabetic eye disease: 11/55 in a younger type 1 diabetes subset; this does not estimate risk in all users., serious (source)
Benign or malignant growths: Postmarketing cases reported. Causation and a reliable cancer incidence are unknown., serious. New lumps, changing moles or other growths need prompt medical review. (source)
Hip growth-plate slip or bone tissue death: Reported in children; frequency unknown., serious. New limp or hip/knee pain needs prompt evaluation. (source)
Benzyl-alcohol toxicity in neonates and infants: The label warns of serious and fatal reactions with benzyl alcohol preserved drugs; this is not an incidence estimate for Increlex., serious. Increlex contains 9 mg/mL benzyl alcohol. Its label does not recommend use in infants; safety and effectiveness below age 2 are not established. (source)

Stop and get help if

Confusion, seizure, fainting or persistent low blood sugar: Stop dosing and get emergency care. Do not give food or drink to an unconscious person.
Breathing trouble, throat/facial swelling or widespread hives: Stop dosing and get emergency care.
Severe or persistent headache, vomiting or new vision changes: Stop dosing and seek urgent evaluation for raised pressure around the brain.
New limp or hip/knee pain: Get prompt care for hip growth-plate slip or bone tissue death.
Chest pain, collapse or severe breathlessness: Get emergency care now.
New or changing lump, mole or other abnormal growth: Stop dosing and arrange prompt specialist assessment.

Who should avoid it

under18: Increlex itself is approved from age 2; this app block is not an FDA pediatric contraindication.
pregnant: No adequate human pregnancy data. The EU label says not to use during pregnancy.
breastfeeding: Milk transfer and infant effects are unknown.
tryingToConceive: This is a precaution. The EU label advises pregnancy testing and contraception during treatment.
activeCancer: Active or suspected neoplasia is a stop condition. Discontinue if a tumor develops.
cancerHistory: The US label excludes pediatric patients with prior malignancy; EU/UK restrictions include cancer-predisposing history.
other: Do not re-expose after a serious reaction to mecasermin or an ingredient.
other: Do not use for height gain after growth plates close. Adult bones cannot lengthen through this mechanism.
other: Food must be available around each dose. Withhold a dose when the meal or snack is omitted.
diabetes: Glucose-lowering treatment may need adjustment; low blood sugar can be severe.
diabeticRetinopathy: One IGF-1/insulin trial reported early retinal worsening at higher doses.
seizureDisorder: Hypoglycemia can cause seizures or loss of consciousness.
sleepApnea: Tonsil/adenoid enlargement may worsen snoring or obstructed breathing.
heartCondition: Fluid retention and cardiac changes warrant review; cardiac causation in growth studies was uncertain.
kidneyDisease: No established dose adjustment for children with primary IGF-1 deficiency and kidney disease.
liverDisease: No established dose adjustment for children with primary IGF-1 deficiency and liver disease.
surgeryPlanned: Fasting may require withheld doses and adjusted glucose-lowering treatment.
other: Raised brain pressure is a risk; eye checks are recommended before and during treatment.
other: Rapid growth can worsen an existing spinal curve.
testedAthlete: WADA prohibits mecasermin at all times under S2.3.

Interactions

Insulin: Doses may need reduction because of additive low blood sugar. Insulin co-treatment in trials required close glucose checks.
Sulfonylureas and other insulin releasers: Other glucose-lowering medicines may need reduction. No formal interaction study defines a dose change.
Other IGF-1 products: No safe schedule is established for combining IGF-1 products.
Growth hormone and secretagogues: Pediatric GH combinations were studied in selected patients; this does not establish a safe adult or secretagogue stack.
Anticoagulants and antiplatelets: No interaction studies are available. Injection-site bruising and bleeding have been reported.

Product quality risks

Unregulated IGF-1 analogues are not interchangeable with licensed mecasermin. A tested LR3 vial contained an extra purification tag.
No current market-wide survey of counterfeit or underdosed Increlex was located. Specific counterfeit-pen rates are unknown.
A research-use-only label or purity percentage does not establish identity, amount, sterility or freedom from endotoxin.

How Mecasermin works

Mecasermin replaces IGF-1, a growth signal normally made in response to growth hormone. It helps growth-plate cells grow and tissues take up nutrients. It can also lower blood sugar. Once growth plates have closed, it cannot make bones longer.

IGF-1 receptor: Supports cell growth and growth-plate activity.
Glucose metabolism: Increases tissue glucose uptake and reduces glucose output from the liver.

Half-life: Mean 5.8 hours in 3 people with severe primary IGF-1 deficiency after one injection under the skin.

Gaps: The humanStudies count is a minimum of screened original human reports, not independent trials; cohorts and follow-up papers overlap. No established adult bodybuilding, recovery or longevity protocol. Earlier native rhIGF-I studies cannot validate LR3. Long-term malignant cancer risk remains uncertain; voluntary reports cannot give a reliable incidence. Some older trial abstracts have apparent dose-unit errors. No MS or transplant dosing protocol is built from those values. Exact placebo-arm outcomes and adverse-event rates were unavailable for some older studies. Those numbers are not reconstructed. Formal interaction studies, pregnancy data and breastfeeding data are lacking. No reliable native-mecasermin community dose could be separated from molecule and unit confusion. The schema lacks not-applicable for biologic compounding. Regulatory category is unclear only for that encoding reason. Registry-only protocols are shown in study arms; no fixed titration is invented when registry or publication data are incomplete.

Related to Mecasermin

IGF-1 LR3: An unapproved growth signal with no human trials found.
Somatropin: Prescription human growth hormone, with no proven anti-aging benefit.

Mecasermin: the short version

Sources

Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act, FDA · FDA · 2026
Compounding and the FDA: Questions and Answers, FDA · FDA · 2026
Purple Book Search, FDA · 2026
The 2026 Prohibited List, World Anti-Doping Agency · WADA · 2026
Therapeutic Goods (Poisons Standard—October 2026) Instrument 2026, Australian Government · Australian Government · 2026
INCRELEX (mecasermin) current prescribing information, revised October 2025, Eton Pharmaceuticals, Inc. · DailyMed / Eton Pharmaceuticals · 2025
INCRELEX (mecasermin) injection, for subcutaneous use, U.S. Food and Drug Administration · FDA · 2025
INCRELEX (mecasermin) injection, for subcutaneous use, U.S. Food and Drug Administration · FDA · 2024
Notice to Compounders: Changes that affect compounding as of March 23, 2020, FDA · 2020
Tailor Made Compounding LLC - 594743 - 04/01/2020, FDA · FDA · 2020
AusPAR: Mecasermin, Therapeutic Goods Administration
Increlex, European Medicines Agency
Increlex, INN-mecasermin, European Medicines Agency
Know When to Go to the ER, American College of Emergency Physicians · American College of Emergency Physicians
Mecasermin (Increlex▼): risk of benign and malignant neoplasia, MHRA

Sources checked: 2026-10-18.

Information only, not medical advice. Peptifacts does not sell anything and does not link to sellers.