Mecasermin (recombinant IGF-1, Increlex)
rhIGF-1, rhIGF-I, Recombinant human IGF-1, Mecasermin rinfabate, Iplex, Somazon
Forms: Mecasermin (Increlex) is IGF-1 alone; mecasermin rinfabate is IGF-1 bound to its carrier protein IGFBP-3, the form tested in recreational athletes.
Recombinant human IGF-1, a prescription drug. It carries the growth signal that GH sends through IGF-1 and also acts like insulin, so it lowers blood sugar.
Legal status: Prescription medicine for rare growth disorders in children; WADA bans IGF-1 and its analogues. Rules vary by country.
What it gives
What people use it for and what the sources report. Strength is a general category from the literature: mild, clear or strong.
Purpose
Medical: growth failure in children with severe primary IGF-1 deficiency. In sport: used as 'IGF-1' for muscle growth and recovery; in a 4-week trial in recreational athletes it did not change lean or fat mass.
What people seek and what studies show
Used for muscle growth, recovery and fat loss. In a placebo-controlled trial in 56 recreational athletes, 28 days of IGF-1 bound to IGFBP-3 did not change lean or fat mass, while VO2max rose by about 7%. In children with severe IGF-1 deficiency it improves growth. In obese adults with type 2 diabetes it gave fair sugar control in about half, but side effects stopped treatment in all seven.
Effects
Evidence: Approved medicine — studied in people for its medical use
Possible side effects
With an extreme-risk substance some of these can be life-threatening or permanent; no dose, test or early sign makes it safe. Below — what each risk looks like; the signs that need urgent help are in block 04.
9 possible side effects
level · how often it is reportedHow to lower the risks
Extreme risk. No measure makes using this substance for sport safe: severe, including life-threatening, consequences are possible. The only reliable way to avoid these risks is not to use it.
If a doctor prescribed this medicine to treat you, do not stop taking it on your own — discuss it with your doctor.
Warning signs that need urgent help are listed in block 04.
Check-ups and blood tests
For an extreme-risk substance there is no testing schedule.
Get medical help at once if
- Shaking, cold sweat, sudden hunger, confusion — fast sugar at once; very drowsy, unable to swallow or unconscious — nothing by mouth, call emergency services, glucagon if prescribed. Night sweats or nightmares can mean lows in sleep.
- Sudden loss or blurring of vision, flashes, a curtain over sight — seek urgent care.
- A new lump (including in the neck), trouble swallowing or persistent hoarseness, unexplained weight loss, or blood in stool or urine — see a doctor promptly.
- Racing or irregular heartbeat that does not settle at rest, dizziness, fainting, chest pain — call emergency services.
- Rapid weight gain with breathlessness, or swelling of one leg — see a doctor promptly.
- A hot, red, swollen or pus-filled injection site with fever — signs of an abscess; see a doctor.
In an emergency, call your local emergency number.
For women
Not androgenic; low blood sugar and the other effects apply to women as to men. There are no human data in pregnancy or breastfeeding.
Myth & fact
“Pharmacy IGF-1 builds muscle directly, without growth hormone's downsides.”
In a randomized trial in recreational athletes, 28 days of an IGF-1 complex did not change lean or fat mass, while low blood sugar affected 42% of treated children in the drug's trials.
Combinations
Each of these lowers blood sugar in its own way, so with insulin the lows come deeper, last longer and are harder to predict. Confusion, sweating or drowsiness is an emergency; a severe low can kill.
Insulin (rapid- and short-acting)IGF-1 LR3MetforminSemaglutideTirzepatideRetatrutide (investigational triple agonist)BerberineAlpha-lipoic acidLiraglutideCagrilintide (investigational amylin analogue)DES(1-3) IGF-1IGF-1 LR3 acts like a long-lasting insulin. Other sugar-lowering substances add to it, so lows come deeper and last longer; confusion, sweating or drowsiness is an emergency.
IGF-1 LR3MetforminSemaglutideTirzepatideRetatrutide (investigational triple agonist)BerberineAlpha-lipoic acidLiraglutideCagrilintide (investigational amylin analogue)DES(1-3) IGF-1A racing pulse and tremor are the body's early alarm for low blood sugar. Nebivolol blunts them, so a dangerous low can go unnoticed until it shows as confusion or fainting.
NebivololInsulin (rapid- and short-acting)IGF-1 LR3DES(1-3) IGF-1Glucocorticoids raise blood sugar, after a depot injection often for days, and work against insulin, IGF-1 and GLP-1 drugs. Sugar can run high while the glucocorticoid acts and then fall as its effect wears off while the sugar-lowering drug keeps working. Only glucose checks show these swings.
Insulin (rapid- and short-acting)IGF-1 LR3DES(1-3) IGF-1SemaglutideTirzepatideRetatrutide (investigational triple agonist)LiraglutideA racing pulse is one of the body's early alarms for low blood sugar. Bisoprolol and carvedilol blunt it, so a dangerous low can go unnoticed until it shows as confusion or fainting. Carvedilol, which also blocks beta-2 receptors, can in addition make a low deeper and slower to recover from.
Insulin (rapid- and short-acting)IGF-1 LR3DES(1-3) IGF-1Both are forms of IGF-1 and both lower blood sugar much like insulin, so together the lows come deeper and last longer. Confusion, sweating or drowsiness is an emergency; a severe low can kill.
DES(1-3) IGF-1