Recombinant Somatotropin

Human Growth Hormone (HGH)

A 191-amino acid recombinant protein identical to endogenous somatotropin. The gold standard for direct growth hormone replacement in research settings.

◆ Evidence Level: FDA ApprovedRecombinant human growth hormone (somatropin) is FDA-approved for growth hormone deficiency, Turner syndrome, and other conditions. Extensively studied in clinical trials. See references →

What Is Human Growth Hormone?

Human Growth Hormone (HGH), also called somatotropin, is a 191-amino acid protein produced by the anterior pituitary gland. It is the primary hormone responsible for linear growth, cell regeneration, and tissue repair throughout the body.

Recombinant HGH (rHGH) is a lab-synthesized version structurally identical to the body’s own GH. Unlike secretagogues that stimulate the pituitary to produce more GH, exogenous HGH delivers the hormone directly – bypassing the hypothalamic-pituitary axis entirely.

Mechanism of Action

HGH acts through both direct and indirect pathways:

Direct effects: GH binds to receptors on target cells, stimulating lipolysis (fat breakdown) and opposing insulin’s lipogenic effects
IGF-1 mediation: GH stimulates the liver to produce IGF-1, which drives most anabolic effects including muscle protein synthesis and bone growth
Cell proliferation: Promotes chondrocyte and osteoblast activity for connective tissue and bone remodeling
Metabolic regulation: Increases glucose output, shifts fuel utilization toward fatty acids, and supports nitrogen retention
Recovery: Accelerates tissue repair, wound healing, and collagen synthesis throughout the body

Research Applications

Direct GH replacement for age-related somatotropin decline
Body recomposition: fat loss with simultaneous lean mass support
Accelerated injury recovery and connective tissue repair
Skin elasticity, hair quality, and anti-aging research
Sleep architecture improvement and deep sleep enhancement
Bone density and joint health studies in aging models

Dosing Protocol

Recombinant HGH is administered via subcutaneous injection, typically once daily. Dosing is measured in international units (IU):

Protocol	Dose	Frequency	Notes
Anti-aging	1–2 IU	Once daily	Morning or pre-bed; long-term use
Body recomp	2–4 IU	Once daily	Morning fasted; 5 on / 2 off common
Recovery	4–6 IU	Split AM/PM	Advanced; monitor blood glucose

Start low and titrate up over 2–4 weeks to assess tolerance. Monitor fasting blood glucose and IGF-1 levels. Common protocols cycle 5 days on / 2 days off or run continuously for 3–6 months.

Preparation & Storage

Administration

This compound typically comes pre-mixed and ready to inject. Use an insulin syringe (29–31 gauge) for subcutaneous administration.

Clean the vial top and injection site with alcohol swabs
Draw your dose into the syringe
Pinch skin at the injection site (abdomen or thigh)
Insert needle at a 45–90° angle and inject slowly
Rotate injection sites to prevent tissue irritation

Storage

Refrigerate at 2–8°C (36–46°F)
Use within the timeframe specified on label
Do not freeze
Keep away from direct sunlight

Cycling

Typical protocol: 3–6 months. Results generally reported within 4–6 weeks.