Human Growth Hormone (Somatropin)

FDA-approved prescription biologic (indication-specific)

Somatropin (rhGH) is a 191-amino-acid recombinant human growth hormone used as an FDA-approved prescription biologic for specific pediatric and adult indications; activates GHR → IGF-1 axis to drive growth and metabolic effects.

Calculate Dose

For research use only.

Key Facts

CAS: 12629-01-5
Molecular Weight (MW): 22124 g/mol
Half-life: ~3 hours (SC/IM absorption-limited; serum decline ~3–5 hours)
Unit: IU
Administration Route: Subcutaneous (most common); IM less common
Frequency: Typically daily (clinical replacement); varies by indication
Last updated: 2/23/2026
Targets: Growth hormone receptor (GHR)IGF-1 axis

Overview

Protocol

Dosage Range: Individualized dosing (weight/IGF-1 guided in clinical use)
Frequency: Typically daily (clinical replacement); varies by indication
Cycle: Use only per FDA labeling / prescriber direction (indication-specific)
Administration Route: Subcutaneous (most common); IM less common
Reconstitution Guide: Reconstitute only with supplied diluent or bacteriostatic water per product instructions (varies by brand/device)

May vary by vendor concentration and protocol.

Science

Mechanism of Action

Agonist at GHR → activates JAK/STAT signaling and downstream IGF-1 production; promotes linear growth in pediatrics (open epiphyses) and shifts protein/fat metabolism in adults.

Targets

Growth hormone receptor (GHR)IGF-1 axis

Studies

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Benefits

Treats growth hormone deficiency (indication-specific)Improves linear growth in eligible pediatric conditionsCan improve lean mass and reduce fat mass in GH-deficient patientsSupports bone density over time in deficiency states