Human growth hormone (HGH, GH) is a protein hormone made by the pituitary gland. The drug version, somatropin, is made by recombinant DNA technology and has the same amino acid sequence as the natural hormone. In the US it is approved for children with several growth disorders, for adults with diagnosed growth hormone deficiency, and (as Serostim) for HIV-associated wasting.
Outside medicine, HGH is used for anti-aging and bodybuilding. In US federal law it has a special status: it is not a controlled substance, but distributing it for any use other than an FDA-approved one, prescribed by a physician, is a felony. In controlled trials in healthy people it reliably adds lean body mass, but much of that gain is water, and it has not been shown to increase strength.
This page summarizes what the FDA labels, clinical trials and regulators report. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Drug class | Recombinant peptide hormone (somatropin): 191 amino acids, 22,124 daltons |
| US brands | Genotropin, Humatrope, Norditropin (each first approved 1987), Serostim, others; weekly analogs such as Sogroya |
| Route | Subcutaneous injection |
| Labeled adult GHD dose | About 0.2 mg/day to start (range 0.15–0.30 mg/day), adjusted by IGF-1 levels |
| Labeled HIV-wasting dose | 0.1 mg/kg once daily, up to 6 mg (Serostim) |
| Half-life (labels) | About 0.4 h after IV dosing; 3.0–3.8 h after subcutaneous dosing (up to 7–10 h in one label) |
| Bioavailability | About 80% after subcutaneous injection |
| US legal status | Not a controlled substance; distribution for unapproved uses is a federal felony |
| WADA status | Prohibited at all times (class S2.2.3) |
What it is
Somatropin is a single-chain protein of 191 amino acids with a molecular weight of 22,124 daltons. The label states that its sequence is identical to growth hormone of pituitary origin (Genotropin label). Because it is a protein, it is destroyed in the gut and must be injected.
The body releases GH from the pituitary. Daily secretion rises through childhood, peaks in adolescence and then declines steadily. Sleep, exercise and stress all increase release (DEA fact sheet).
GH binds growth hormone receptors on cells throughout the body. Its effects, as described in the labels, include:
- Growth: in children, it acts on the growth plates of long bones and raises blood levels of IGF-1 (insulin-like growth factor 1).
- Protein: it increases protein synthesis and nitrogen retention.
- Fat: it mobilizes stored fat and raises blood fatty acids.
- Glucose: it lowers insulin sensitivity, so large doses can impair glucose tolerance.
- Salt and water: it causes retention of sodium, potassium and phosphorus.
From cadavers to recombinant DNA
Before recombinant GH, the hormone was extracted from the pituitary glands of cadavers. Contaminated batches transmitted Creutzfeldt-Jakob disease (CJD), a fatal prion brain disease. In the US National Hormone and Pituitary Program, all 22 CJD cases among 5,570 recipients occurred in people who started treatment before 1977, when a new purification step was introduced (Abrams et al., JCEM 2011). FDA approved synthetic GH in 1985 (DEA fact sheet).
Long-acting analogs
Newer products are modified so they can be injected once a week instead of daily. Somapacitan (Sogroya), for example, binds reversibly to albumin in the blood, which slows its elimination. It was first approved in 2020 and is labeled for adults with GH deficiency and for several pediatric growth disorders (Sogroya label). WADA names lonapegsomatropin, somapacitan and somatrogon as prohibited GH analogs (WADA 2026).
Pharmacokinetics
GH is cleared quickly from the blood. After subcutaneous injection, though, it is absorbed slowly from the injection site, so the apparent half-life is several times longer than after an intravenous dose. It is broken down like other proteins, in the liver and kidneys.
| Parameter | Value | Source |
|---|---|---|
| Bioavailability (subcutaneous vs IV) | About 80% (95% CI 70.5–92.1%) | Genotropin label |
| Time to peak after subcutaneous dose | About 6 h | Genotropin label |
| Half-life, IV | 0.4 h (Genotropin); about 21 min (Norditropin) | Genotropin and Norditropin labels |
| Half-life, subcutaneous | 3.0 h (Genotropin); 3.8 h (Humatrope); about 7–10 h (Norditropin) | Genotropin, Humatrope and Norditropin labels |
| Circulating vs “biological” half-life | 20–30 min in blood; biological half-life 9–17 h, reflecting indirect effects | DEA fact sheet |
Because GH levels swing quickly, the labels use IGF-1 levels, not GH levels, to guide dosing.
Approved medical use
The indications vary slightly by brand. Across the Genotropin, Norditropin and Humatrope labels, they include:
- Children: growth failure from GH deficiency, Turner syndrome, Prader-Willi syndrome, Noonan syndrome, SHOX deficiency, being born small for gestational age without catch-up growth, and idiopathic short stature;
- Adults: replacement in GH deficiency that began in adulthood (from pituitary or hypothalamic disease, surgery, radiation or trauma) or in childhood;
- HIV-associated wasting or cachexia in adults also taking antiretroviral therapy (Serostim only) (Serostim label).
The Genotropin label says adult GH deficiency usually needs to be confirmed with a GH stimulation test. Labeled doses from the Genotropin and Serostim labels:
| Population | Labeled dose |
|---|---|
| Adult GH deficiency, non-weight-based | About 0.2 mg/day (0.15–0.30 mg/day), raised by 0.1–0.2 mg/day every 1–2 months based on response and IGF-1 |
| Adult GH deficiency, weight-based | Start at no more than 0.04 mg/kg/week; up to no more than 0.08 mg/kg/week |
| Pediatric GH deficiency | 0.16–0.24 mg/kg/week, divided into 6–7 daily injections |
| Turner syndrome | 0.33 mg/kg/week |
| HIV-associated wasting (Serostim) | 0.1 mg/kg once daily at bedtime, up to 6 mg |
The adult label advises lower starting doses for older patients and notes that obese patients are more prone to side effects on weight-based dosing. Women taking oral estrogen may need higher doses. The Endocrine Society guideline concludes that GH replacement improves body composition, exercise capacity, bone and quality of life in adults with GH deficiency, with the most benefit in severe deficiency (Molitch et al., JCEM 2011).
What the research shows
Adults with GH deficiency
In six randomized trials, 172 adults with GH deficiency received Genotropin or placebo for 6 months, followed by open-label treatment for up to 24 months. GH increased lean body mass and total body water and reduced fat mass and waist circumference. Bone mineral density fell after 6 months, then returned to baseline by 12 months (Genotropin label).
A meta-analysis of 37 blinded, randomized, placebo-controlled trials in GH-deficient adults pooled these effects (Maison et al., JCEM 2004):
| Outcome | Change with GH vs placebo |
|---|---|
| Lean body mass | +2.7 kg |
| Fat mass | −3.1 kg |
| LDL cholesterol | −0.5 mmol/L (≈ −19 mg/dL) |
| Total cholesterol | −0.3 mmol/L (≈ −12 mg/dL) |
| Diastolic blood pressure | −1.8 mm Hg |
| Fasting glucose | +0.2 mmol/L (≈ +4 mg/dL) |
| Fasting insulin | +8.7 pmol/L |
The authors concluded that GH improves body composition and cholesterol but reduces insulin sensitivity. Whether it lowers heart attacks or deaths has not been shown.
HIV-associated wasting
The larger Serostim trial randomized 757 adults with HIV-associated wasting to placebo or about 0.1 mg/kg every other day or daily for 12 weeks (Serostim label):
| Outcome at 12 weeks | Placebo | 0.1 mg/kg every other day | 0.1 mg/kg daily |
|---|---|---|---|
| Lean body mass | +0.97 kg | +3.89 kg | +5.84 kg |
| Fat mass | +0.03 kg | −1.25 kg | −1.72 kg |
| Body weight | +0.69 kg | +2.18 kg | +2.79 kg |
| Cycling work output | +0.2% | +8.9% | +9.1% |
Lean mass rose with dose, but work output improved about equally with half the dose. The label suggests considering every-other-day dosing in people at higher risk of side effects.
Healthy older adults (“anti-aging”)
Interest in GH as an anti-aging drug traces to a 1990 study. Twelve healthy men aged 61–81 with low IGF-1 received about 0.03 mg/kg three times a week for 6 months, compared with 9 untreated men. The treated men gained 8.8% lean body mass and lost 14.4% fat mass (Rudman et al., NEJM 1990). The study was small and had no placebo group.
A larger 26-week placebo-controlled trial randomized 131 healthy adults aged 65–88 to GH, sex steroids, both, or placebo in a factorial design (Blackman et al., JAMA 2002). GH started at 30 µg/kg three times a week, later reduced to 20 µg/kg.
| Men | Lean body mass change |
|---|---|
| Placebo | +0.1 kg |
| Testosterone | +1.4 kg |
| GH | +3.1 kg |
| GH + testosterone | +4.3 kg |
GH also lowered fat mass. Strength, however, did not rise significantly, except for a borderline 13.5 kg gain with GH plus testosterone in men (p = 0.05). Side effects were common, and 18 GH-treated men developed diabetes or glucose intolerance, compared with 7 men not on GH.
A systematic review pooled 18 randomized study populations of healthy older adults (220 GH recipients, mean age 69, mean dose 14 µg/kg/day for a mean of 27 weeks) (Liu et al., Ann Intern Med 2007):
| Outcome | GH vs no GH |
|---|---|
| Fat mass | −2.1 kg (95% CI −2.8 to −1.35) |
| Lean body mass | +2.1 kg (95% CI 1.3 to 2.9) |
| Body weight | +0.1 kg (not significant) |
| Bone density | No change |
| Side effects | More edema, joint pain, carpal tunnel syndrome and gynecomastia; somewhat more new diabetes and impaired fasting glucose |
The authors concluded that GH cannot be recommended as an anti-aging therapy.
Healthy young adults and athletes
A 2008 systematic review pooled 27 randomized study samples of healthy, fit adults aged 13–45 (303 GH recipients, mean dose 36 µg/kg/day, mean treatment about 20 days) (Liu et al., Ann Intern Med 2008). It found:
- Lean body mass: +2.1 kg (95% CI 1.3–2.9) versus no GH;
- Strength and exercise capacity: no apparent improvement;
- Lactate during exercise: significantly higher in 2 of 3 studies that measured it;
- Side effects: more soft-tissue swelling and fatigue.
Training studies help explain why extra lean mass does not translate into strength. In 16 young men doing 12 weeks of heavy resistance training, adding GH at 40 µg/kg/day increased fat-free mass more than placebo. Muscle protein synthesis, limb circumference and strength, however, did not increase more (Yarasheski et al., Am J Physiol 1992). A 16-week trial in 23 older men found the same pattern (Yarasheski et al., Am J Physiol 1995). In both, the authors attributed the extra fat-free mass mainly to fluid and non-muscle tissue.
The one trial that found a performance effect randomized 96 recreational athletes (63 men, 33 women) for 8 weeks (Meinhardt et al., Ann Intern Med 2010). Men received placebo, GH 2 mg/day, testosterone 250 mg/week, or both; women received GH or placebo. Results:
- GH lowered fat mass and raised lean body mass, mostly through extracellular water.
- Sprint capacity rose by 0.71 kJ (95% CI 0.1–1.3 kJ), a 3.9% gain, with GH in men and women combined. With GH plus testosterone in men, it rose by 1.7 kJ (8.3%).
- Strength (dead lift), jump height and aerobic capacity did not change significantly.
- The sprint gain was gone 6 weeks after stopping.
“GH builds muscle.” In healthy people, GH consistently raises measured lean body mass by about 2 kg. Trials that looked closer found that much of this is water and non-contractile tissue, with no added muscle protein synthesis or strength when combined with training. The only performance gain shown in a controlled trial was a small, short-lived increase in sprint capacity.
Side effects and risks
Somatropin labels carry no boxed warning, but they list several serious warnings and contraindications.
Increased deaths in critical illness
Two parallel randomized trials gave high-dose GH (about 0.10 mg/kg/day) or placebo to 532 adults in intensive care after heart or abdominal surgery, multiple trauma, or acute respiratory failure (Takala et al., NEJM 1999):
| Trial | Mortality on GH | Mortality on placebo | Relative risk (95% CI) |
|---|---|---|---|
| Finnish (n = 247) | 39% | 20% | 1.9 (1.3–2.9) |
| Multinational (n = 285) | 44% | 18% | 2.4 (1.6–3.5) |
Among survivors, GH also prolonged intensive-care stays and mechanical ventilation. Acute critical illness is now a contraindication on the labels.
Fluid retention, joint pain and nerve compression
These are the most common side effects in adults. They usually appear early and are dose-dependent, and they often ease with dose reduction. In Genotropin’s adult trials, the first 6 months of double-blind treatment showed these rates (Genotropin label):
| Adverse event | Placebo (n = 572) | GH (n = 573) |
|---|---|---|
| Peripheral swelling | 5.1% | 17.5% |
| Joint pain (arthralgia) | 4.2% | 17.3% |
| Pain in the extremities | 5.9% | 14.7% |
| Peripheral edema | 2.6% | 10.8% |
| Tingling (paresthesia) | 1.9% | 9.6% |
| Stiffness of the extremities | 1.6% | 7.9% |
At the higher doses used for HIV wasting, rates were higher still. With Serostim 0.1 mg/kg daily, 36.4% of patients reported joint pain (vs 11.3% on placebo), 30.4% muscle pain (vs 11.7%) and 26.1% peripheral edema (vs 2.8%). Gynecomastia occurred in 5.5% (vs 0.4%). About 23% of patients on the daily dose needed a dose reduction (Serostim label).
Glucose intolerance and diabetes
GH works against insulin. The labels warn that it can unmask impaired glucose tolerance or diabetes, and that new-onset type 2 diabetes has been reported. Glucose should be monitored periodically, especially in people with obesity or a family history of diabetes. In the trials above, GH raised fasting glucose and insulin in GH-deficient adults. In healthy older men, diabetes or glucose intolerance developed in 18 men on GH vs 7 men not on GH (p = 0.006).
Tumors and long-term mortality
The labels contraindicate GH in active cancer. They report an increased risk of a second tumor, mainly meningiomas, in childhood cancer survivors who had radiation to the head. They also advise monitoring existing moles for growth.
Long-term data from childhood treatment are mixed:
- France: in 6,928 adults treated as children with recombinant GH from 1985–1996, all-cause mortality was higher than in the general population (standardized mortality ratio 1.33, 95% CI 1.08–1.64). It was higher still with doses over 50 µg/kg/day. Overall cancer deaths were not increased, but deaths from bone tumors, circulatory disease and brain hemorrhage were (Carel et al., JCEM 2012).
- Belgium, the Netherlands and Sweden: among 2,543 similar patients, 21 deaths occurred, 76% from accidents or suicide. None were from cancer or cardiovascular disease (Sävendahl et al., JCEM 2012).
These are observational studies, so they cannot prove that GH caused the deaths.
Other labeled warnings
- Intracranial hypertension: raised pressure in the skull, with headache, vision changes and nausea, usually within the first 8 weeks; it resolves after stopping or reducing the dose.
- Hypothyroidism and low cortisol: GH can unmask underactive thyroid or adrenal function in people with pituitary disease.
- Pancreatitis: rare reports, more often in children.
- Children: slipped capital femoral epiphysis (a hip growth-plate injury) and worsening of existing scoliosis.
- Prader-Willi syndrome: deaths have been reported in severely obese children or those with sleep apnea or airway obstruction.
- Injection site: lipoatrophy (loss of fat under the skin) if the same site is used repeatedly.
- Allergy: serious hypersensitivity reactions, including anaphylaxis, have been reported after marketing.
Interactions
The Genotropin label lists these interactions:
| Drug | Interaction |
|---|---|
| Glucocorticoids (cortisone acetate, prednisone, replacement steroids) | GH inhibits 11β-HSD1, the enzyme that activates cortisone, so cortisol falls; replacement doses may need to rise |
| Drugs metabolized by CYP450 enzymes (sex steroids, corticosteroids, anticonvulsants, cyclosporine) | GH may increase their clearance; monitor carefully |
| Oral estrogen | Women may need larger GH doses |
| Insulin and other diabetes drugs | Doses may need adjustment |
Who should not use it
The labels contraindicate somatropin in people with:
- acute critical illness after open-heart or abdominal surgery, multiple trauma, or acute respiratory failure;
- active cancer;
- active proliferative or severe non-proliferative diabetic retinopathy;
- Prader-Willi syndrome with severe obesity, sleep apnea, airway obstruction or severe breathing problems;
- closed growth plates, when GH is used to promote growth;
- known hypersensitivity to somatropin or its ingredients.
Monitoring
The labels call for these checks during treatment:
| What | Why |
|---|---|
| IGF-1 | To titrate the dose in adults; lower the dose if IGF-1 is above the age- and sex-specific range |
| Blood glucose | GH can unmask or worsen diabetes |
| Thyroid function | Central hypothyroidism may appear or worsen |
| Eye exam (fundoscopy) | To detect papilledema from intracranial hypertension, before and during treatment |
| Signs of tumor progression | In people with a history of pituitary or brain tumors |
Legal status and use outside medicine
Under 21 U.S.C. 333(e), knowingly distributing or possessing HGH with intent to distribute for any human use other than an FDA-authorized use ordered by a physician is punishable by up to 5 years in prison. If the offense involves someone under 18, the maximum is 10 years. The law defines HGH as somatropin, somatrem or an analog of either (21 U.S.C. 333). A systematic review notes that distributing GH as an anti-aging agent is therefore illegal in the US (Liu et al., 2007).
The DEA confirms that HGH is not controlled under the Controlled Substances Act (DEA fact sheet). It describes several sources of illicit supply:
- physicians prescribing it for unapproved uses or without examining the patient;
- internet pharmacies and anti-aging or wellness clinics;
- theft, smuggling and counterfeit products.
In sport, GH and its analogs and fragments are prohibited at all times, in and out of competition, under class S2.2.3 of the WADA Prohibited List (WADA 2026). GH-releasing drugs such as sermorelin, tesamorelin and ibutamoren, and fragments such as HGH fragment 176-191, are banned under S2.2.
Key takeaways
- An approved drug with narrow uses. Somatropin is approved for childhood growth disorders, adult GH deficiency and HIV wasting, not for aging, fat loss or athletic performance.
- Short half-life, slow absorption. GH has a half-life of about 0.4 h after IV dosing and about 3–10 h after subcutaneous injection. The labels use IGF-1, not GH, to guide dosing.
- Lean mass is not the same as muscle. In healthy adults GH adds about 2 kg of lean mass, largely water. Trials show no consistent gain in strength, and only a small, transient sprint benefit.
- Side effects are common and dose-dependent. Swelling, joint pain, tingling and carpal tunnel syndrome are frequent. Glucose intolerance and new diabetes are the main metabolic risks.
- Serious risks in specific settings. High doses roughly doubled deaths in critically ill patients. GH is contraindicated in active cancer.
- Legally distinct. HGH is not a controlled substance in the US, but distributing it for unapproved uses is a federal felony, and WADA bans it at all times.
Sources
- Pfizer. Genotropin (somatropin) for injection, prescribing information. DailyMed.
- Eli Lilly and Company. Humatrope (somatropin) for injection, prescribing information. DailyMed.
- Novo Nordisk. Norditropin (somatropin) injection, prescribing information. DailyMed.
- EMD Serono. Serostim (somatropin) for injection, prescribing information. DailyMed.
- Novo Nordisk. Sogroya (somapacitan-beco) injection, prescribing information. DailyMed.
- Drug Enforcement Administration, Diversion Control Division. Human Growth Hormone. Drug and Chemical Evaluation Section fact sheet, July 2026. DEA.
- 21 U.S.C. 333(e), Prohibited distribution of human growth hormone. United States Code, 2023 edition. govinfo.
- World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026. WADA.
- Molitch ME, Clemmons DR, Malozowski S, et al. Evaluation and treatment of adult growth hormone deficiency: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96(6):1587–1609. PubMed.
- Maison P, Griffin S, Nicoue-Beglah M, et al. Impact of growth hormone (GH) treatment on cardiovascular risk factors in GH-deficient adults: a metaanalysis of blinded, randomized, placebo-controlled trials. J Clin Endocrinol Metab. 2004;89(5):2192–2199. PubMed.
- Abrams JY, Schonberger LB, Belay ED, et al. Lower risk of Creutzfeldt-Jakob disease in pituitary growth hormone recipients initiating treatment after 1977. J Clin Endocrinol Metab. 2011;96(10):E1666–E1669. PubMed.
- Rudman D, Feller AG, Nagraj HS, et al. Effects of human growth hormone in men over 60 years old. N Engl J Med. 1990;323(1):1–6. PubMed.
- Blackman MR, Sorkin JD, Münzer T, et al. Growth hormone and sex steroid administration in healthy aged women and men: a randomized controlled trial. JAMA. 2002;288(18):2282–2292. PubMed.
- Liu H, Bravata DM, Olkin I, et al. Systematic review: the safety and efficacy of growth hormone in the healthy elderly. Ann Intern Med. 2007;146(2):104–115. PubMed.
- Liu H, Bravata DM, Olkin I, et al. Systematic review: the effects of growth hormone on athletic performance. Ann Intern Med. 2008;148(10):747–758. PubMed.
- Yarasheski KE, Campbell JA, Smith K, et al. Effect of growth hormone and resistance exercise on muscle growth in young men. Am J Physiol. 1992;262(3 Pt 1):E261–E267. PubMed.
- Yarasheski KE, Zachwieja JJ, Campbell JA, Bier DM. Effect of growth hormone and resistance exercise on muscle growth and strength in older men. Am J Physiol. 1995;268(2 Pt 1):E268–E276. PubMed.
- Meinhardt U, Nelson AE, Hansen JL, et al. The effects of growth hormone on body composition and physical performance in recreational athletes: a randomized trial. Ann Intern Med. 2010;152(9):568–577. PubMed.
- Takala J, Ruokonen E, Webster NR, et al. Increased mortality associated with growth hormone treatment in critically ill adults. N Engl J Med. 1999;341(11):785–792. PubMed.
- Carel JC, Ecosse E, Landier F, et al. Long-term mortality after recombinant growth hormone treatment for isolated growth hormone deficiency or childhood short stature: preliminary report of the French SAGhE study. J Clin Endocrinol Metab. 2012;97(2):416–425. PubMed.
- Sävendahl L, Maes M, Albertsson-Wikland K, et al. Long-term mortality and causes of death in isolated GHD, ISS, and SGA patients treated with recombinant growth hormone during childhood in Belgium, The Netherlands, and Sweden: preliminary report of 3 countries participating in the EU SAGhE study. J Clin Endocrinol Metab. 2012;97(2):E213–E217. PubMed.