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Growth hormone

Somatropin (HGH)

Prepared by the ezGLP team. Sources last checked . Profile reviewed .

Also known as Human Growth Hormone

Routes represented in the knowledgebase: Subcutaneous (SubQ).

Educational overview

Somatropin (HGH) is listed in the ezGLP knowledgebase under Growth hormone. Evidence and regulatory status can vary by formulation, route, and jurisdiction.

Somatropin is recombinant human growth hormone, a 191-amino-acid single-chain protein with a molecular weight of about 22,124 daltons whose sequence, according to the Genotropin prescribing information, is identical to pituitary-derived human growth hormone. It is the hormone itself rather than a secretagogue: where sermorelin, CJC-1295, or ipamorelin prompt the pituitary to release its own stores, somatropin acts directly on growth hormone receptors in liver, bone, muscle, and adipose tissue and raises IGF-1 independently of pituitary function. Somatropin products are biologics measured historically in international units of bioactivity as well as in milligrams, which is why catalogue entries often carry both.

Growth hormone replacement has been studied in randomised trials since recombinant production replaced cadaveric pituitary extract in the 1980s, and the approved indications rest on registration programs in each population. Evidence about healthy adults is a separate question. Liu and colleagues published a systematic review in Annals of Internal Medicine in 2008 covering placebo-controlled studies of growth hormone in healthy participants, and reported that administration increased lean body mass, largely through fluid retention, without a demonstrated improvement in strength or exercise capacity, alongside more frequent soft-tissue oedema, joint pain, carpal tunnel syndrome, and impaired glucose tolerance.

Somatropin is an FDA-approved prescription biologic, but only for defined indications. The Genotropin label covers growth failure in children due to growth hormone deficiency, Prader-Willi syndrome, small size for gestational age, Turner syndrome, and idiopathic short stature, plus adults with childhood-onset or adult-onset deficiency; other brands add HIV-associated wasting and short bowel syndrome. Contraindications include acute critical illness, active malignancy, closed epiphyses in children, and severe obesity or respiratory impairment in Prader-Willi syndrome. USADA states that off-label growth hormone is unlawful and a felony under the Food, Drug, and Cosmetic Act, and that growth hormone is prohibited in sport at all times, with a therapeutic use exemption required.

Presentations differ widely, and the specific product label governs handling. Genotropin is supplied as a lyophilised powder in two-chamber cartridges and single-dose devices; the label directs refrigerated storage at 2 to 8 degrees Celsius, protection from light, and no freezing, allows the smallest single-dose devices up to three months at or below 25 degrees Celsius before reconstitution, and limits a reconstituted multi-dose cartridge to 28 days refrigerated. Other brands ship as prefilled pens or as vials reconstituted with diluent. The subcutaneous half-life reported in the Genotropin label is 3.0 hours in adults with growth hormone deficiency, so an inventory record generally tracks presentation, strength, lot, first-use date, and the 28-day or product-specific in-use window.

Category
Growth hormone
Routes represented
Subcutaneous (SubQ)
Approximate library half-life
3 hours; formulation-dependent and not dosing guidance
Storage context
Follow the dispensed product or pharmacy label; storage and beyond-use time vary by formulation.

Published literature

No verified PubMed or DOI link is available for this entry.

Safety evidence

Common or reported: edema, joint or muscle pain, tingling or carpal-tunnel symptoms, headache, injection-site reactions.

Serious or important: intracranial hypertension, glucose intolerance or diabetes, adrenal insufficiency, pancreatitis, malignancy-related warnings.

Safety evidence source

Interaction evidence

These are general, pairwise evidence notes. Green identifies the potential-synergy category, while Lv3/Lv2/Lv1 communicates evidence strength; it does not guarantee benefit or cancel a safety warning.

With glucocorticoid replacement

Safety flag

GH-axis stimulation can reduce cortisone-to-cortisol conversion and unmask or worsen adrenal insufficiency.

Interaction evidence source

With glucose-lowering medicines

Safety flag

GH-axis stimulation can reduce insulin sensitivity and alter glucose control.

Interaction evidence source

With Ipamorelin

Safety flag

Duplicate GH/IGF-axis stimulation may amplify IGF-1 elevation, edema, joint symptoms, and glucose intolerance.

Interaction evidence source

Common questions

Is somatropin FDA approved?

Yes, for specific indications rather than in general. Labels across brands cover growth hormone deficiency in children and adults, Prader-Willi syndrome, Turner syndrome, small size for gestational age, idiopathic short stature, chronic kidney disease in children, SHOX deficiency, HIV-associated wasting, and short bowel syndrome, depending on the product. No somatropin product is approved for anti-aging, bodybuilding, athletic performance, or general wellness, and labels list contraindications including active malignancy and acute critical illness.

Is HGH illegal in the United States?

Growth hormone is a prescription biologic, but United States law treats it differently from other prescription drugs. Distribution or possession with intent to distribute human growth hormone for uses other than those authorised by the FDA and ordered by a physician is a criminal offence under the Food, Drug, and Cosmetic Act. USADA describes off-label growth hormone as unlawful and a felony, and cites Drug Enforcement Administration statements about wellness and anti-aging marketing.

Does HGH build muscle in healthy adults?

The systematic review evidence is unfavourable. Liu and colleagues examined placebo-controlled studies of growth hormone in healthy participants in Annals of Internal Medicine in 2008 and found that lean body mass increased, attributed largely to fluid retention, with no demonstrated gain in strength or exercise capacity. Reported adverse effects were more frequent than with placebo and included soft-tissue swelling, arthralgia, carpal tunnel syndrome, and impaired glucose tolerance.

Is growth hormone banned in sport?

Yes. Growth hormone is prohibited at all times, in and out of competition, on the World Anti-Doping Agency Prohibited List, which also covers its fragments and releasing factors. USADA notes the prohibition applies to elite, junior, and masters athletes alike and that an approved therapeutic use exemption is required even when growth hormone is prescribed for a recognised medical condition. Accredited laboratories run both isoform and biomarker tests for growth hormone.

What is the difference between somatropin and a growth hormone secretagogue?

Somatropin supplies growth hormone directly and works regardless of pituitary output, so the resulting exposure is set by the administered amount rather than by the pituitary. Secretagogues such as sermorelin, CJC-1295, ipamorelin, and GHRP-2 act on GHRH or ghrelin receptors to prompt the pituitary to release its own hormone, which preserves feedback from IGF-1 and somatostatin. Somatropin is approved for defined indications; the secretagogues in this catalogue are not.

Further reading

Summarised from published literature for reference only, with citations to the source. Evidence is graded as reported and is not a recommendation to combine, dose, or use any compound.

For personal tracking and education only. Not medical advice, diagnosis, or treatment, and not a medical device. Peptides may be prescription-only or unapproved where you live. Consult a licensed healthcare professional.