What is HGH?

What sources report

For people with a diagnosed deficiency or another labeled condition, somatropin has been a prescription treatment since its first US approval in 1987, and a 2011 Endocrine Society guideline judges its risks low in deficient adults.¹¹⁵ For healthy adults, the evidence comes mostly from small trials, and reviewers describe small changes in body composition with more adverse events.⁵

How it works

Growth hormone-releasing hormone from the hypothalamus makes pituitary somatotroph cells build growth hormone and release it in pulses, and ghrelin from the stomach also switches production on.³² In 149 healthy men aged 16 to 83, growth hormone secretion was linked to slow wave (deep) sleep independent of age, and fell by about 372 micrograms per decade from early adulthood to midlife as deep sleep declined.¹⁶ Release peaks in puberty and reaches a low point near age 55.²

Its targets include chondrocytes (cartilage), osteoblasts (bone), myocytes (muscle), hepatocytes (liver) and adipocytes (fat), and IGF-1 made in the liver and other tissues carries part of the signal.³ In deficient patients, the label describes three metabolic effects: the body retains more nitrogen, a sign of protein building; stored fat is mobilized into the blood as fatty acids; and large doses can impair glucose tolerance.¹

After an injection under the skin, about 80% of a Genotropin dose reaches the circulation.¹ Its half-life is about 3.0 hours that way in adults with deficiency, against 0.4 hours when given into a vein in healthy adults.¹ Standard somatropin is given daily, while the long-acting analogue lonapegsomatropin is usually injected once a week.⁸¹⁷

What the trials found

Read together, the trials in healthy people show about 2 kg more lean mass, partly water, without a clear gain in strength.⁵¹⁹²⁰ The 2008 reviewers concluded that claims of better physical performance are not supported by the scientific literature.¹⁹

What has not been shown

• Anti-aging: the 2007 review found small body composition changes and more adverse events, and concluded GH cannot be recommended as an anti-aging therapy.⁵
• Weight loss: in older adults, fat fell but lean mass rose by the same amount, so weight did not change.⁵ Weight loss is not among the labeled uses.⁴
• Sleep: the link with deep sleep does not show that adding GH improves sleep. In 8 adults aged 20 to 30 with isolated deficiency, 6 months of treatment shortened total sleep and lengthened REM sleep, with no significant change in deep sleep.²²
• Skin: in the 1990 study of older men, skin thickness rose 7.1%, which did not reach significance (P = 0.07).¹⁸
• Healing: the burn trials were small and at risk of bias.²¹ None of the labeled uses covers recovery from exercise or sports injury.⁴

The goal pages map these searches: Peptides and muscle growth, Peptides and weight loss, Peptides and sleep and Peptides and healing and recovery.

How it compares

Sermorelin and Tesamorelin are GHRH analogues: they ask the pituitary for more of its own growth hormone instead of supplying it.¹¹³ Tesamorelin, the 44-amino-acid GHRH sequence plus a hexenoyl group, is FDA approved only to reduce excess abdominal fat in adults with HIV and lipodystrophy, and its label calls it weight neutral.³ WADA groups Ipamorelin, ibutamoren and macimorelin as secretagogues and lists GHRP-2 and GHRP-6 as GH-releasing peptides.¹⁰

HGH Fragment 176-191 and AOD-9604 are short pieces from the C-terminal end of HGH, and WADA bans both as growth hormone fragments.²³¹⁰ In obese mice, long-term treatment with HGH or AOD9604 caused weight loss.²³ The HGH research vial is listed at HGH for sale; it is not a licensed somatropin product.

Side effects

The Genotropin label's adverse event table covers adults with diagnosed deficiency during the first 6 months of placebo-controlled treatment.¹ Most events were mild to moderate signs of fluid retention.¹ Every row below was significantly more common than on placebo except headache and fatigue.¹

Injection-site reactions, rashes and lipoatrophy (loss of fat under the skin where injections are repeated) are also common.¹ Label warnings and trials add more:

• Critical illness: in two ICU trials of 522 adults without deficiency, deaths were 42% on somatropin at 5.3 to 8 mg a day versus 19% on placebo. It is contraindicated in acute critical illness from complications of open heart surgery, abdominal surgery or multiple accidental trauma, and in acute respiratory failure.¹
• Blood sugar: it can lower insulin sensitivity and unmask impaired glucose tolerance or diabetes, and new type 2 diabetes has been reported.¹ In adults with burns, high blood sugar was 2.43 times as likely as on placebo.²¹
• Tumors: it is generally contraindicated with active cancer, and childhood cancer survivors given head radiation had a higher risk of a second tumor, especially meningioma.¹
• Pressure in the skull: intracranial hypertension with optic disc swelling, vision changes, headache, nausea or vomiting, usually within the first 8 weeks.¹
• Allergy: anaphylaxis and angioedema have been reported after marketing.¹
• Other hormones: low cortisol or low thyroid function can surface in people with pituitary problems, and women on oral estrogen may need a larger dose.¹
• Children: deaths in children with Prader-Willi syndrome and severe obesity or breathing problems, a hip disorder (slipped capital femoral epiphysis) and worsening scoliosis.¹
• Rare: pancreatitis, with some evidence of greater risk in children.¹
• Older adults: the label has no trial data for people 65 and over.¹ In the JAMA trial, swelling was more common in women given GH (39% vs 0%), and the authors said GH use in the elderly should be confined to controlled studies.¹³

Dosage information

A prescriber sets every somatropin dose for a diagnosed condition and adjusts it by clinical response, side effects and age- and sex-adjusted IGF-I levels.¹ The label schedules are written in mg:

Older patients start lower and increase in smaller steps.¹ Trials in healthy people used research doses: initial daily doses averaging 14 micrograms per kg in older adults, an average of 36 micrograms per kg a day in young, fit adults, and 2 mg a day for 8 weeks in recreational athletes.⁵¹⁹²⁰ No dose is approved for anti-aging, bodybuilding or fat loss, and these study figures are not guidance for any person.⁵⁴

US labels write somatropin doses in mg.¹ The international unit (IU) is a historical unit; the WHO International Standard converts at 3.0 IU per mg of somatropin.²⁴

Reconstitution and storage

Mixing and storage rules come from the licensed products' labels:

• Before mixing: Genotropin and Zomacton powders are refrigerated at 2 to 8 °C (36 to 46 °F) and protected from light, and Genotropin must not be frozen.¹²⁵ Genotropin MiniQuick devices may stay at or below 25 °C (77 °F) for up to 3 months before mixing.¹
• Mixing: the Zomacton label says to aim the diluent stream at the vial wall to prevent foaming, then swirl the vial gently until the solution is clear. Shaking clouds it, and the Genotropin label says shaking may denature the protein.²⁵¹
• After mixing: Genotropin cartridges keep up to 28 days refrigerated. Zomacton 5 mg vials keep 14 days with bacteriostatic sodium chloride (0.9% benzyl alcohol), and 10 mg vials keep 28 days with bacteriostatic water (0.33% metacresol).¹²⁵
• Inspection: a cloudy solution, or one with particles, is not used.¹
• Diluent caution: serious and fatal reactions, including "gasping syndrome", can occur in newborns and infants given benzyl alcohol-preserved drugs, such as the diluent packed with Zomacton 5 mg.²⁵

These limits belong to licensed products, and no stability study of research-labeled vials was found. Lab steps and the math are in How to reconstitute a peptide vial, the Reconstitution calculator and How to store peptides.

Regulatory status

United States

Somatropin was first approved in the US in 1987, and MedlinePlus lists 11 US brands, one of them (Nutropin) no longer on the market.¹⁴ It is prescription only. Since March 23, 2020, approved somatropin products have been regulated as biologics, which FDA says are not eligible for the 503A and 503B compounding exemptions.¹²⁶²⁷

Labeled uses vary by brand: growth failure in children (deficiency, Prader-Willi syndrome, small for gestational age, Turner syndrome and idiopathic short stature), adult deficiency, HIV-associated wasting and short bowel syndrome.¹⁸⁴

Under 21 U.S.C. 333(e), knowingly distributing HGH, or possessing it with intent to distribute, for any human use other than HHS-authorized, physician-ordered treatment of a disease or recognized medical condition is punishable by up to 5 years in prison, or 10 years when someone under 18 is involved.⁹ The law covers somatrem, somatropin and analogues of either; convictions count as Controlled Substances Act felonies for forfeiture, and DEA may investigate.⁹ DailyMed lists the somatropin product Serostim with "DEA Schedule: None".⁸

FDA has not approved somatropin for anti-aging, and the 2007 review states that distributing it for that purpose is illegal in the US.⁵

Sport and other countries

WADA's 2026 Prohibited List, in force from January 1, 2026, bans growth hormone, its analogues (lonapegsomatropin, somapacitan, somatrogon) and fragments (AOD-9604, hGH 176-191) at all times under S2.2.3.¹⁰ It also bans GHRH analogues, secretagogues and GH-releasing peptides, along with IGF-1 and its analogues.¹⁰ In the European Union, Omnitrope is a prescription-only biosimilar of Genotropin, authorized EU-wide on April 12, 2006.²⁸