Somatropin (HGH)

Recombinant human growth hormone (rhGH) - the reference point for the entire GH axis.

ClinicalFDA-approvedInjectableHigh risk

Key facts

Common routesSubcutaneous

Half-life~3-4 hours

Typical range0.1-0.3 mg/day (titrated)

Summary

Somatropin is recombinant human growth hormone (rhGH): a 191-amino-acid protein identical to endogenous pituitary GH. As a prescription biologic (Genotropin, Humatrope, and others), it's approved for growth hormone deficiency and selected growth disorders. Mechanistically, GH activates the growth hormone receptor (JAK/STAT), elevates hepatic and peripheral IGF-1, and drives systemic growth and recovery signaling.

This is the actual biomolecule - every GH secretagogue on the site (Ipamorelin, CJC-1295, Tesamorelin) is trying to stimulate the release of this. In a performance context, that makes HGH the reference. It also carries the highest risk profile of the GH peptides: exogenous supply shuts down endogenous production, side effects are meaningfully dose- and duration-dependent, and counterfeits are everywhere.

Mechanism notes

Growth hormone receptor (JAK/STAT)

Somatropin binds and dimerizes the GH receptor, activating JAK2 and driving the STAT signaling cascade. This is the pharmacological starting point for all GH effects - systemic rather than localized.

IGF-1 axis activation

Raises circulating and tissue IGF-1. IGF-1 mediates most of the desired effects (recovery, body recomposition) - and most of the practically relevant risks (unwanted tissue growth, anti-insulin effect).

Lipolysis + metabolic effects

GH promotes lipolysis and antagonizes insulin signaling. That explains the lipolytic effect on one side, and the fasting-glucose rise in susceptible users on the other - a risk parameter that needs routine monitoring.

Dosing patterns

Medical protocol (GHD)

Starting dose typically 0.1-0.3 mg/day in adults with diagnosed GH deficiency, subcutaneous once daily (usually evening). Titrated to IGF-1 target range, tolerability, and side-effect profile. This is individualized dosing, not a fixed range - interindividual sensitivity is large.

Non-medical use (reality)

Community use is most commonly expressed in IU/day (not mg) and regularly exceeds medical replacement dosing. Low single-digit IU/day is typical, with sharply increasing side-effect rates at higher doses or when stacked with AAS/insulin. Duration is the main driver of irreversible changes.

Evidence snapshot

For approved indications (adult and pediatric GH deficiency) there are decades of studies, guidelines, and post-marketing data (Molitch et al. 2011 - Endocrine Society guideline). For anti-aging and recovery use in healthy adults the evidence is much weaker: Liu et al. (2007) summarized modest body-composition effects with higher adverse-event rates.

Approved indications

Adult and pediatric GH deficiency, Turner syndrome, chronic renal insufficiency, SHOX deficiency, and others - each with established dosing and monitoring protocols.

Healthy adults (off-label)

Modest body-composition effects alongside meaningfully higher adverse-event rates - the systematic review (Liu 2007) does not find a favorable risk/benefit for anti-aging use.

Safety considerations

Somatropin is not a “gentle” recovery peptide - it's a systemic hormone with dose- and duration-dependent consequences. Short-term side effects (edema, joint pain, carpal tunnel symptoms, elevated fasting glucose) are common and reverse on dose reduction. Long-term abuse can drive acromegaly-like changes and organ enlargement - and those don't reverse.

Key cautions

Exogenous HGH downregulates endogenous GH production - unlike GH secretagogues (Ipamorelin / Tesamorelin), recovery can take months after cessation
Dose-dependent edema, joint pain, carpal tunnel symptoms, and insulin resistance - glucose and blood pressure monitoring is not optional
HGH is one of the most heavily counterfeited peptides; IGF-1 bloodwork is the only reliable way to verify potency