Growth hormone
Mecasermin (IGF-1)
Prescription IGF-1 replacement for certain pediatric growth disorders; a different context from enhancement claims.
Medical uses / indication-specific evidence
Also known as: Increlex · rhIGF1
Practical use
Applying the explained evidence
- Where it fits
- Prescription IGF-1 replacement for certain pediatric growth disorders; a different context from enhancement claims.
- Put the information into practice
- Pediatric replacement evidence does not establish a benefit-risk balance for adult bodybuilding. Similar names do not make research analogues equivalent to a prescription product.
- Outcome versus a marker
- Separate a change in a hormone measurement or body-composition estimate from the outcome you actually care about. Look for direct measurement of function, symptoms and adverse events.
- Keep this limit in view
- Four studies were open-label. These data address severe pediatric deficiency, not adult height, bodybuilding or the effects of different IGF analogs.
Overview
Mecasermin replaces insulin-like growth factor in children with inadequate production and impaired growth. Its medical use is diagnosis-specific; it is not simply interchangeable with every product sold under an IGF-1 label.
Risks and limitations
Low blood sugar is a central risk and can become severe. Other important concerns include visual symptoms, headache, sleep-related breathing problems and serious allergic reactions. Cancer history and growth-plate status affect suitability.
How to read this
Pediatric replacement evidence does not establish a benefit-risk balance for adult bodybuilding. Similar names do not make research analogues equivalent to a prescription product.
Research explained
Growth velocity in severe primary IGF-1 deficiency
Who was studied
The label summarizes five studies involving 71 pediatric patients. The height-velocity analysis had 58 evaluable patients at baseline and year one.
- Pretreatment height velocity
- 2.8 cm/year
- First-year height velocity
- 8 cm/year
What was found
Mean height velocity increased from 2.8 to 8.0 cm/year during the first year. The reported comparison is with pretreatment growth, not a parallel placebo group of 58 patients.
What it cannot establish
Four studies were open-label. These data address severe pediatric deficiency, not adult height, bodybuilding or the effects of different IGF analogs.
Read the original studySafety and pharmacokinetics
Mecasermin is recombinant IGF-1. Among 71 treated subjects, 30 (42%) experienced hypoglycemia at least once; five had severe episodes and four had seizures or loss of consciousness. Fourteen of the 30 already had a history of hypoglycemia.
The label’s estimated 5.8-hour half-life comes from subcutaneous treatment in children with severe primary IGF-1 deficiency. It is not an adult performance-use measurement or evidence about IGF-1 LR3.
Supporting sourceSources
Growth velocity in severe primary IGF-1 deficiency
Sources checked 2026-09-28.
General education; not a personal treatment plan.