HGH

Somatropin · Human Growth Hormone · rHGH

Rank#999
Growth HormoneApprovedApprovedPrescriptionSubQIM

Popular for:Growth hormone deficiency, anti-aging, body composition

4681

Total Studies

3670

Human Studies

Approved

Evidence Level

Approved

FDA Status

Overview

Human Growth Hormone (HGH), also known as somatropin, is a 191-amino acid single-chain polypeptide produced by the anterior pituitary gland. Recombinant human growth hormone (rhGH) is manufactured using recombinant DNA technology and is bioidentical to endogenous GH. It is FDA-approved for multiple growth and metabolic conditions and is one of the most extensively studied hormones in medicine.

> HGH (somatropin) is a CONTROLLED SUBSTANCE. Distribution without a valid prescription is a FEDERAL FELONY under 21 USC § 333(e). Penalties include up to 5 years imprisonment for distribution and up to 10 years for distribution to minors. This is NOT a grey-area research chemical — it is explicitly regulated by the FDA and DEA.

Mechanism of Action

GH binds to the growth hormone receptor (GHR), activating the JAK2-STAT5 signaling pathway. It stimulates hepatic production of IGF-1 (insulin-like growth factor 1), which mediates many of GH's anabolic effects. Direct GH effects include lipolysis (fat breakdown), gluconeogenesis, and protein synthesis. IGF-1 effects include bone growth, muscle growth, collagen synthesis, and cellular proliferation. GH is released in pulsatile fashion, with the largest pulse occurring during Stage 3/4 NREM sleep.

Key Research Benefits

Body composition: Reduces body fat (especially visceral fat) and increases lean body mass. Rudman et al. (1990, NEJM) landmark study showed 14.4% fat mass decrease and 8.8% lean mass increase in elderly men over 6 months.
Bone density: GH replacement increases bone mineral density over long-term use (12-18+ months). Particularly beneficial in GH-deficient adults.
Tissue repair and recovery: Enhances collagen synthesis, tendon and ligament repair, wound healing. Used clinically in burn recovery.
Sleep quality: GH replacement improves deep sleep quality (slow-wave sleep), which in turn supports further endogenous GH release.
Skin and hair: Improved skin thickness, elasticity, and hydration through collagen production. Often cited as an anti-aging benefit.
Cardiovascular: GH replacement in GH-deficient adults improves lipid profiles and may reduce cardiovascular risk markers.

Clinical Evidence Summary

Research Pipeline

Preclinical
Animal
Phase I
Phase II
Phase III
Approved

4681

Total Studies

3670

Human Studies

- Rudman et al. (1990) — Landmark NEJM study. 12 elderly men received GH for 6 months. 14.4% decrease in fat mass, 8.8% increase in lean mass, 1.6% increase in vertebral bone density. Catalyzed the anti-aging GH movement.

- Liu et al. (2007) — Systematic review of 31 RCTs (Ann Intern Med). GH in healthy elderly increased lean mass by ~2 kg and decreased fat mass by ~2 kg, but increased edema, arthralgia, carpal tunnel, and glucose impairment.

- FDA-approved indications include: adult GH deficiency, pediatric GH deficiency, Turner syndrome, Prader-Willi syndrome, chronic renal insufficiency, SGA (small for gestational age), idiopathic short stature, short bowel syndrome, and HIV-associated wasting.

- KIMS database — Largest long-term GH replacement safety registry with data on >20,000 adults. No increased cancer incidence observed with replacement-dose GH.

Key Studies / PubMed References

4,681 studies found on PubMed · showing top 25 by relevance

View all on PubMed

Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.

In Vitro

Lee T, Lee D, Jung E, et al. · PloS one · 2025

PMID: 40373007

Weight loss-independent changes in human growth hormone during water-only fasting: a secondary evaluation of a randomized controlled trial.

Human Study

Horne BD, Anderson JL, May HT, et al. · Frontiers in endocrinology · 2024

PMID: 39991046

Silica-collagen nanoformulations with extended human growth hormone release.

Review

Villarruel LA, Brie B, Municoy S, et al. · International journal of pharmaceutics · 2023

PMID: 36736675

Topical Delivery of Cell-Penetrating Peptide-Modified Human Growth Hormone for Enhanced Wound Healing.

In Vitro

Nguyen TV, Lee KH, Huang Y, et al. · Pharmaceuticals (Basel, Switzerland) · 2023

PMID: 36986493

Amino acid substitutions in human growth hormone affect secondary structure and receptor binding.

Review

Rajkovic A, Kanchugal S, Abdurakhmanov E, et al. · PloS one · 2023

PMID: 36952491

Side Effects & Safety

> GH side effects are dose-dependent. Low-dose replacement (1-2 IU) carries significantly less risk than high-dose performance use (4-8+ IU).

Common: Water retention/edema, joint pain (arthralgia), carpal tunnel syndrome, numbness/tingling in extremities, headache, elevated fasting glucose
Serious: Insulin resistance/type 2 diabetes, acromegaly-like symptoms (jaw/hand growth at high chronic doses), increased cancer risk (IGF-1 promotes cell proliferation), intracranial hypertension
Bodybuilding-specific: 'GH gut' (visceral organ growth at sustained high doses), gynecomastia when combined with androgens, hypothyroidism (GH increases T4→T3 conversion)
Contraindications: Active malignancy, diabetic retinopathy, acute critical illness, closed epiphyses in pediatric patients (for growth), Prader-Willi syndrome with severe respiratory impairment
Drug interactions: Glucocorticoids (antagonize GH), insulin (GH causes insulin resistance — may need dose adjustment), thyroid hormones, oral estrogen (reduces IGF-1 response)

Known Interactions

No curated interaction entry is live for HGH yet.

Until the interaction table is fully populated, use the interaction checker and related peptides below to explore adjacent compounds and likely research pairings.

Frequently Asked Questions

Research Disclaimer

This page is for research and educational purposes only. The information presented is based on published scientific literature and does not constitute medical advice, diagnosis, or treatment recommendations. HGH is not approved by the FDA for human therapeutic use. Always consult a qualified healthcare professional before making any health-related decisions. The studies referenced are linked to their original PubMed sources for verification.