Increlex

Much of this compound class has never been through a human safety trial. Rather than say nothing — or print a generic warning — this is what its known mechanism predicts could go wrong, and what you can do about it. Predictions are labelled as predictions.

What the mechanism predicts

Derived from what this molecule does, not from a trial.

• This is IGF-1 itself, not something that asks your body for IGF-1. Every other compound on the GH axis in this Vault works by persuading the pituitary to pulse and the liver to respond, and the liver's regulatory step is also a brake. Delivering the finished hormone removes that brake, which is why the risk profile here is sharper than anything upstream of it.
• Hypoglycaemia is the dose-limiting risk, and it is not a rare one. IGF-1 has real activity at the insulin receptor. In the registration trials 42% of patients had hypoglycaemia and five had severe episodes involving seizure or loss of consciousness. That is one of the very few numbers on any card in this Vault that comes from a label rather than from a mechanism.
• IGF-1 is a growth signal for lymphoid tissue: tonsillar and adenoidal hypertrophy is documented at 15%, and it progresses to snoring, obstructive sleep apnoea and middle-ear effusion.
• Intracranial hypertension — headache with nausea and visual change — was reported in roughly 4%.
• Where growth plates are still open, the label carries slipped capital femoral epiphysis and progression of scoliosis. Those are paediatric findings and they are the reason a limp or new hip or knee pain is treated as urgent rather than as a training niggle.
• The proliferation question that runs through the whole GH axis is sharper here for the same reason everything else is: this is the growth signal itself, and growth signals do not distinguish between tissue you want and tissue you do not.

What has actually been reported

• Unusually for this section of the Vault, all of the above is observed rather than predicted. Increlex is an approved drug with a real label and real trial numbers behind every figure quoted here.
• What is NOT observed is any of it in healthy adults using it for body composition. Every number comes from children with severe primary IGF-1 deficiency — a population whose IGF-1 started near zero. That is not the population reading this page.

How to reduce the risk

Each of these follows from the same mechanism as the prediction.

• Eat with it — within about twenty minutes either side of a meal or snack. This is the label instruction and it is the single most important line on this card. It is also the exact opposite of how the GH secretagogues on neighbouring pages are timed, which are usually taken fasted to avoid blunting the pulse. Carrying the fasted habit across from the compound next to it on the shelf is the realistic way somebody gets hurt with this drug.
• Do not drive or train hard for two to three hours after a dose until you know your own response.
• Learn what your hypoglycaemia feels like — shaking, sweating, confusion, sudden hunger — and keep fast carbohydrate within reach of where you inject. The severe cases in the trials were seizures, and a seizure is what an untreated hypo eventually becomes.
• New snoring or daytime sleepiness is the lymphoid arm reporting in, not a coincidence. Persistent headache with nausea or visual change is the intracranial arm, and it needs eyes looked at rather than a dose adjustment.

What it does to your bloodwork

A fact about the assay, not a guess about the drug.

• Fasting glucose and HbA1c before you start, because the dose-limiting risk is a glucose risk and you want the comparison.
• IGF-1 itself — and note that an IGF-1 drawn while running this is measuring the injection, not your axis. If you want a real baseline, draw it first.
• A funduscopic examination is the label's recommendation at initiation and periodically, which is unusual enough to be worth taking literally.

Don't run this if

• Active malignancy or any history of it. This is a labelled contraindication, not a caution.
• Closed epiphyses, where the purpose is growth — also a labelled contraindication.
• The formulation contains benzyl alcohol, which carries serious and fatal reactions in infants and is a reason the paediatric labelling is specific about who may receive it.

The honest unknown

• What direct IGF-1 does to an adult whose GH axis is already intact and whose IGF-1 is already normal. The entire evidence base is replacement in deficiency; the entire off-label use is addition on top of sufficiency. Those are different questions and only one has been asked.

Not medical advice. If you take prescription medication or have a diagnosed condition, check this with a pharmacist or doctor.

Predicted from mechanism, not from an interaction study. There are no trials of these combinations — what follows is what the biology implies, so treat it as a reason to watch something, not as a finding.

What Increlex moves on your bloodwork

These are the markers this compound is expected to move, and which direction. Knowing that in advance is mostly about NOT panicking: some of these moving is the compound working.

• IGF-1 (Insulin-like Growth Factor 1) — ↑ expected to rise
  This is the point. IGF-1 rising is the compound doing its job — it is the stable downstream readout of a GH pulse.
  What to do: Test it before you start and again at 6–8 weeks. It is the only number that tells you whether the product was real and the dose was enough.
• Growth Hormone, Serum — ✕ unreliable here
  A random GH level is close to meaningless here. GH is secreted in pulses during deep sleep and sits undetectable between them, so a daytime draw catches a trough almost every time — including when the compound is working perfectly.
  What to do: Do not use GH to judge a secretagogue. Read IGF-1 instead.
• Fasting Insulin — ↑ expected to rise
  GH is a counter-regulatory hormone: it opposes insulin. Fasting insulin and glucose drifting up is the predicted trade-off, not a surprise.
  What to do: Check fasting insulin and HbA1c at baseline and again at 8–12 weeks. This is the marker that decides whether you keep running it.
• HbA1c (Hemoglobin A1c) — ↑ expected to rise
  Same mechanism, longer window — a slow drift rather than a jump.
  What to do: Pair it with fasting insulin; either alone can mislead.
• Free T4 (Thyroxine) — ↓ expected to fall
  GH accelerates the peripheral conversion of T4 to T3, so free T4 can fall while free T3 holds or rises. Read alone it looks like new hypothyroidism, and it usually isn't.
  What to do: Run a full thyroid panel rather than TSH alone before concluding anything.

Everything above follows from one fact: these raise GH and therefore IGF-1. Nothing here needs a trial of the specific molecule.