Somatropin
Somatropin is FDA-approved recombinant human growth hormone identical in sequence to endogenous pituitary GH, used clinically for GH deficiency, Turner syndrome, Prader-Willi syndrome, and other approved indications. In wellness and performance contexts it is studied for body composition, anti-aging, and recovery, though off-label use raises significant regulatory and safety considerations.
Written by WhatPeptide Editorial Team · Last updated 2026-03-17
Half-life
Approximately 3-4 hours (subcutaneous)
Dosage range
0.1-0.3 mg/day subcutaneously for GH deficiency (clinical literature); higher non-labeled exposure ranges carry increased risk
Administration
Subcutaneous injection
Research level
Strong
How Somatropin works
Somatropin binds the GH receptor (GHR) and activates the JAK2/STAT5 signaling cascade, stimulating hepatic IGF-1 production which mediates downstream anabolic and metabolic effects. Direct GH receptor activation also promotes lipolysis in adipocytes and protein synthesis in skeletal muscle independently of IGF-1. Exogenous HGH suppresses endogenous GH axis feedback and must be used cautiously in healthy individuals due to risks of acromegalic sequelae, insulin resistance, and potential cancer promotion.
Also known as: HGH, Human Growth Hormone, Recombinant Human Growth Hormone, rhGH
Research relevance
Side effects & safety
Contraindications
Consult a healthcare provider before use if any of these apply to you.
Key studies
-
de la Motte S et al. — Somatropin SC PK with two injection systems
Somatropin metabolic t½ ~20-30 min (IV); observed terminal t½ 2-4 hours after SC administration
PubMed 2001 -
Dehkhoda F et al. — GH receptor: mechanism of activation and cell signaling
GH activates JAK2-STAT5 signaling; JAK2 required for STAT1, STAT3, STAT5 activation
PubMed 2018 -
Chow JC et al. — GH stimulates JAK2/STAT5 phosphorylation in vivo
In vivo GH stimulates tyrosine phosphorylation of JAK2 and STAT5 in liver and skeletal muscle
PubMed 1996 -
Genotropin (somatropin) Prescribing Information
FDA label 2024 -
Norditropin (somatropin) Prescribing Information
FDA label 2024
FAQ
What is Somatropin? + −
What is Somatropin researched for? + −
What are the side effects of Somatropin? + −
Is Somatropin FDA approved? + −
How is Somatropin administered? + −
Explore similar peptides
CJC-1295
Moderate evidenceGH Secretagogue
A modified GHRH analog designed to prolong endogenous GH pulse support through albumin binding (DAC form). Originally placed on FDA Category 2 list (September 2023), then removed September 27, 2024 when the nominator withdrew. FDA still lists it under 'Other bulk drug substances that may present significant safety risks.' Regulatory status remains uncertain.
GHRP-2
Moderate evidenceGrowth Hormone Releasing Peptide
A potent synthetic GH secretagogue with human endocrine data demonstrating acute GH pulse stimulation.
Ipamorelin
Moderate evidenceGrowth Hormone Releasing Peptide
A selective ghrelin-receptor agonist studied for stimulating GH release with less prolactin/cortisol impact than older GHRPs. Originally placed on FDA Category 2 list (September 2023), then removed September 27, 2024 when the nominator withdrew. FDA still lists it under 'Other bulk drug substances that may present significant safety risks.' Regulatory status remains uncertain.
MK-677
Moderate evidenceGH Secretagogue
An oral non-peptide ghrelin receptor agonist often discussed with GH peptides due to GH/IGF-1 stimulating effects. Placed on FDA Category 2 list (September 29, 2023) as 'Ibutamoren mesylate.'