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Growth Hormone
FDA Approved

HGH

HGH

Recombinant growth hormone, the reference standard for the GH axis.

Also known as: Somatropin, Human Growth Hormone

Research dose range1–4 IU daily (research models)
Route studiedSubcutaneous
Study durationDaily, multi-week to multi-month studies
Storage2–8 °C reconstituted

Overview

Somatropin is recombinant human growth hormone, the central anabolic hormone of the somatotropic axis. It is among the most studied hormones in growth, metabolism, and body-composition research.

Key research findings

Recombinant human growth hormone (somatropin) is identical to endogenous GH and is the reference standard for the GH axis. It drives IGF-1 production, protein synthesis, lipolysis, and tissue growth — the downstream target that secretagogues and GHRH analogs aim to stimulate indirectly.

Mechanism of action

Binds growth-hormone receptors to drive IGF-1 production in the liver and peripheral tissues, influencing protein synthesis, lipolysis, and cellular growth.

Molecular information

Weight22,124 Da
Length191 amino acids
TypeRecombinant human growth hormone (somatropin)

Single-chain polypeptide identical to pituitary-derived GH; far larger than the peptide secretagogues.

Pharmacokinetics

Peak: ~2–6 hoursHalf-life: ~2–4 hours (subcutaneous)Cleared: ~24 hours
Peak · 2hHalf-life · 12h

Illustrative relative-concentration model derived from published pharmacokinetic research. Curve is normalized and provided for educational comparison only — not a dosing schedule.

Research applications

  • Growth and development research
  • Body-composition and metabolic studies
  • IGF-1 axis investigations

Research protocols

Protocols summarized from published research models. Provided for scientific reference only — not dosing guidance for human use.

Conservative referenceAmount: 1–2 IUFrequency: Once dailyRoute: Subcutaneous
Standard referenceAmount: 2–4 IUFrequency: Once daily (often AM)Route: Subcutaneous

Observed effects timeline

Aggregated observations reported across research literature. Timing and magnitude vary by model and are not a guarantee of outcome.

  1. Week 1–4

    IGF-1 elevation and early changes in recovery/sleep reported in study cohorts.

  2. Week 8–12

    Body-composition and connective-tissue changes reported.

  3. Ongoing

    Effects reverse after discontinuation; IGF-1 monitoring is standard.

Research compatibility

Describes how compounds are studied alongside one another in the literature. Not a recommendation to co-administer.

IGF-1 LR3

Downstream IGF-1 overlap; combined effects monitored in research.

Use caution

Sermorelin

Redundant GH-axis stimulation.

Use caution

MK-677

Both raise GH/IGF-1 via different routes.

Use caution

BPC-157

Distinct pathways; co-studied in recovery contexts.

Compatible

How to reconstitute

Important

Reconstitute with bacteriostatic water, directing the stream against the vial wall, and swirl very gently — somatropin is fragile and degrades with agitation or heat.

  1. 1Allow the vial to reach room temperature (15–20 minutes).
  2. 2Swab the stopper with alcohol and let it air dry.
  3. 3Add bacteriostatic water slowly down the vial wall — never directly onto the powder.
  4. 4Swirl gently until dissolved — do not shake.
  5. 5Refrigerate at 2–8 °C and use within the labeled window.
Open reconstitution calculator

Quality indicators

Uniform white powder

Lyophilized somatropin should be white and intact without discoloration.

Clear solution

Reconstitutes to a clear, colorless, particle-free solution.

Cold-chain integrity

Highly temperature-sensitive — maintain consistent refrigeration.

Slight clumping

Small clumps that dissolve completely with gentle swirling are acceptable — shipping can cause minor compaction.

Collapsed or melted appearance

Powder that looks collapsed, melted, or stuck to the vial walls may have been exposed to heat in transit.

Cloudy after reconstitution

Persistent cloudiness, particles, or precipitate after gentle mixing can indicate a degraded or contaminated peptide.

Reported observations & safety

Safety signals reported in the research literature. Compiled for scientific awareness — not medical advice.

  • Water retention, joint discomfort, carpal-tunnel symptoms, and insulin/glucose changes are commonly reported.
  • IGF-1 and glucose monitoring are standard in GH-axis research.

References & further reading

Growth hormone physiology and the GH/IGF-1 axis (review)

ReviewGH/IGF-1endocrinology

Overview of GH structure, IGF-1 signaling, and metabolic actions underpinning the entire secretagogue class.

View study

Topics

growth hormoneanabolicigf-1

This entry is provided for educational and informational purposes only. It is not medical advice, a dosing protocol, or a claim of therapeutic benefit. Research compounds are supplied strictly for laboratory and research use — not for human or veterinary consumption.

Research level
FDA Approved

Approved for one or more clinical indications by a major regulator.

Quick reference
Dose range1–4 IU daily (research models)
RouteSubcutaneous
DurationDaily, multi-week to multi-month studies
Storage2–8 °C reconstituted
Half-life~2–4 hours (subcutaneous)
Catalogue status

This compound is part of our educational reference and is not currently stocked. Browse the catalogue for available research-grade peptides.

Browse catalogue
Research toolsReconstitution calculator

Related compounds

IGF-1

IGF-1 LR3

Long-acting insulin-like growth factor analog.

SERM

Sermorelin

Foundational GHRH analog.

TESA

Tesamorelin

Stabilized GHRH analog studied in adipose research.

MK-677

MK-677

Orally active growth-hormone secretagogue.