What does the research show about growth hormone?

Growth hormone

In healthy older adults, growth hormone cut fat by 2.1 kg and added 2.1 kg of lean mass, with no change in weight. In young athletes, lean mass rose but strength and exercise capacity did not. Swelling, joint pain and carpal tunnel syndrome were more common. Two intensive care trials found higher mortality, and a later pooled analysis did not.

Add to Bio HackChecked 2026-11-09

Status: Prescription drug in the US. Somatropin is FDA-approved for adults with adult-onset or childhood-onset growth hormone deficiency, and for children with growth failure from growth hormone deficiency and several other conditions. It is not approved for aging or athletic performance.
Also called: somatropin, HGH, human growth hormone, rhGH, GH, Genotropin, Norditropin, Humatrope, Omnitrope, Saizen, Zomacton
Taken for: anti-aging, muscle gain, fat loss, recovery, athletic performance, strength, longevity

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help4

ModerateShown to lower fat mass about 2.1 kg and raise lean body mass about 2.1 kg in healthy older adults, with no change in weight.
ModerateShown to lower visceral fat modestly and raise thigh muscle area with low-dose growth hormone in adults with obesity and no deficiency.
ModerateShown to raise lean body mass about 3.6% and leg strength about 3.2% in orthopedic and sports medicine patients.
ModerateShown to lower body fat about 2.6 kg and raise lean mass about 1.4 kg in adults with growth hormone deficiency. Quality of life improved in most trials.

Reported risks4

StrongShown to raise swelling, joint pain and carpal tunnel symptoms, with swelling about 6 times as likely in adults with deficiency.How often is not known
ModerateShown to raise fasting glucose and diabetes risk in older adults and adults with obesity. The label warns of glucose intolerance and diabetes.How often is not known
ModerateShown to about double in-hospital deaths at high doses in two intensive care trials. A later review of 23 trials found no mortality change.How often is not known
LimitedLimited evidence: long-term mortality was not raised after childhood treatment for isolated deficiency, while some cancers rose in subgroups. The label warns of neoplasms.How often is not known

What people take it for, and what was found

Shown to help4

Moderate

Body composition in healthy older adults

Shown to lower fat mass about 2.1 kg and raise lean body mass about 2.1 kg in healthy older adults, with no change in weight.

The numbers and sources

Effect: Against no growth hormone, fat mass fell 2.1 kg (95% CI 1.35 to 2.8) and lean body mass rose 2.1 kg (95% CI 1.3 to 2.9). Weight did not change (0.1 kg, 95% CI -0.7 to 0.8). Total cholesterol fell 0.29 mmol/L, not significantly after adjusting for body composition. Bone density and other lipids did not change [1].
Population: 18 study populations with 220 treated participants, mean age 69, mean BMI 28, mean treatment 27 weeks [1].
Sources: [1]
Caveats: Most trials were small, and some outcomes were measured too rarely to pool [1]. The review was funded by AHRQ and the NIA. Lean body mass includes water, not only muscle.

Moderate

Visceral fat and thigh muscle in adults with obesity

Shown to lower visceral fat modestly and raise thigh muscle area with low-dose growth hormone in adults with obesity and no deficiency.

The numbers and sources

Effect: In adults with obesity and no growth hormone deficiency, low-dose growth hormone lowered visceral fat by an SMD of -0.34 (95% CI -0.57 to -0.12) and raised thigh muscle area by 6.33 cm² (95% CI 1.72 to 10.95) against placebo [4].
Population: 420 adults aged 18 to 65 in 10 RCTs lasting 4 to 72 weeks [4].
Sources: [4]
Caveats: Small trials with wide differences in length. Fasting glucose rose (see Risks) [4].

Moderate

Lean mass and leg strength in orthopedic patients

Shown to raise lean body mass about 3.6% and leg strength about 3.2% in orthopedic and sports medicine patients.

The numbers and sources

Effect: Across orthopedic studies, lean body mass rose in 15 of 23 studies, a mean difference of 3.63% against placebo, and leg extension strength rose by a mean difference of 3.17%. IGF-1 rose by a mean of 133.2%, in a dose-dependent way [5].
Population: 1,157 patients, mean age 54.3, in 22 studies of orthopedic surgery and sports medicine settings, mean dose 1.49 mg per day [5].
Sources: [5]
Caveats: The review rated its studies as moderate quality and pooled only where it could [5]. These were patients, not healthy athletes.

Moderate

Body composition and quality of life in growth hormone deficiency

Shown to lower body fat about 2.6 kg and raise lean mass about 1.4 kg in adults with growth hormone deficiency. Quality of life improved in most trials.

The numbers and sources

Effect: In adults with confirmed deficiency, growth hormone lowered weight by 2.31 kg (95% CI 1.96 to 2.66) and body fat by 2.56 kg (95% CI 2.16 to 2.97), and raised lean body mass by 1.38 kg (95% CI 1.10 to 1.65). BMI and bone density did not change. Quality of life improved in 11 of 16 trials, though the data could not be pooled [6].
Population: 54 RCTs with more than 3,400 adults with growth hormone deficiency [6].
Sources: [6]
Caveats: Trial quality was rated fair [6]. These results describe people with a diagnosed deficiency, not healthy adults.

Not shown to help1

Moderate

Strength and performance in healthy young athletes

Not shown to improve strength or exercise capacity in healthy young athletes, though lean body mass rose about 2 kg, mostly water. Sprint capacity rose slightly.

The numbers and sources

Effect: Lean body mass rose 2.1 kg (95% CI 1.3 to 2.9) against no growth hormone, but strength and exercise capacity did not appear to improve. Lactate during exercise was higher in 2 of 3 studies that measured it [2]. In recreational athletes given growth hormone for 8 weeks, sprint capacity rose 0.71 kJ (3.9%, 95% CI 0.0 to 7.7%), and 8.3% in men given testosterone as well. Endurance, strength and jump height did not change. The lean mass gain came from extracellular water, and the sprint gain was gone 6 weeks after stopping [3].
Population: 27 study samples with 303 treated participants aged 13 to 45, mean 27, mean treatment 20 days [2]; 96 recreational athletes, 63 men and 33 women [3].
Sources: [2], [3]
Caveats: Few studies measured performance, and trial doses may differ from covert use [2][3]. [3] was funded by the World Anti-Doping Agency.

Claimed, not studied in people1

Untested

Longer lifespan

Not studied in people as a lifespan outcome. In mice, less growth hormone goes with longer life, the opposite of the claim.

No study in people. This rests on animal studies.

The numbers and sources

Effect: Mice with the growth hormone gene knocked out lived longer than normal mice in both sexes, while weighing less, carrying more body fat as a share of weight and handling glucose less well [13]. Mice lacking growth hormone releasing hormone were long-lived, and calorie restriction lengthened their lives further [14]. In SAMP8 mice, a drug that blocks the growth hormone releasing hormone receptor raised mean life expectancy by 8 weeks, with no rise in maximum lifespan [15].
Population: Growth hormone knockout mice [13]. GHRH knockout mice [14]. SAMP8 mice, a strain with shortened life expectancy [15].
Sources: [13], [14], [15]
Caveats: These studies lowered growth hormone rather than adding it, and mice are not people. No trial has measured lifespan in adults given growth hormone. The mortality findings after childhood treatment are covered under Risks [10].

Doses studied

Trials in healthy older adults used a mean initial dose of 14 µg per kg per day for a mean 27 weeks [1]. Trials in young athletes used a mean 36 µg per kg per day for a mean 20 days [2]. The recreational athlete trial used 2 mg per day for 8 weeks [3]. The orthopedic studies used a mean 1.49 mg per day [5].

Risks

Reported risks3

StrongHow often is not known

Swelling, joint pain and carpal tunnel syndrome

Shown to raise swelling, joint pain and carpal tunnel symptoms, with swelling about 6 times as likely in adults with deficiency.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Healthy older adults on growth hormone were more likely to have soft tissue swelling, joint pain, carpal tunnel syndrome and breast enlargement in men [1]. Young athletes had more swelling and fatigue [2]. In adults with deficiency, the relative risk of swelling was 6.07 (95% CI 4.34 to 8.48) and of joint stiffness 4.17 (95% CI 1.4 to 12.38) [6]. In orthopedic studies, the odds of swelling of the limbs were 3.03, of carpal tunnel symptoms 3.85 and of joint pain 2.94 on growth hormone [5].
Population: As in [1], [2], [6] and [5].
Sources: [1], [2], [6], [5]
Caveats: [1] and [2] report these as more frequent without pooled rates in the abstract.

ModerateHow often is not known

Diabetes and raised blood sugar

Shown to raise fasting glucose and diabetes risk in older adults and adults with obesity. The label warns of glucose intolerance and diabetes.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Healthy older adults on growth hormone were somewhat more likely to develop diabetes and impaired fasting glucose [1]. In adults with obesity, low-dose growth hormone raised fasting glucose by 4.18 mg/dL against placebo (95% CI 0.68 to 7.67) [4]. The somatropin label lists glucose intolerance and diabetes among its warnings [7].
Population: 220 treated older adults [1]; 420 adults with obesity in 10 RCTs [4]; label [7].
Sources: [1], [4], [7]
Caveats: Few events in small trials. The obesity meta-analysis reported no serious adverse events [4].

ModerateHow often is not known

Death in critical illness

Shown to about double in-hospital deaths at high doses in two intensive care trials. A later review of 23 trials found no mortality change.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: In two parallel trials of adults in intensive care, in-hospital mortality was 39% on growth hormone against 20% on placebo in Finland, and 44% against 18% in the multinational trial. Relative risk of death was 1.9 (95% CI 1.3 to 2.9) and 2.4 (95% CI 1.6 to 3.5) [8]. A 2025 meta-analysis of 23 RCTs of growth hormone, nandrolone and oxandrolone in intensive care found mortality unaffected, with longer intensive care and hospital stays. Growth hormone improved nitrogen balance (SMD 1.4, 95% CI 0.47 to 2.32) [9]. The label lists acute critical illness as a contraindication [7].
Population: 532 adults after cardiac or abdominal surgery, trauma or respiratory failure, in intensive care for 5 to 7 days, given a mean 0.10 mg per kg per day [8]; critically ill adults in 23 RCTs [9].
Sources: [8], [9], [7]
Caveats: High doses in very ill patients. It does not describe healthy adults. The meta-analysis reported substantial heterogeneity and a concerning risk of bias, and the two large trials and the pooled result disagree on mortality [9].

Mixed results1

LimitedHow often is not known

Cancer, tumor recurrence and long-term mortality

Limited evidence: long-term mortality was not raised after childhood treatment for isolated deficiency, while some cancers rose in subgroups. The label warns of neoplasms.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: In 24,232 people treated in childhood, all-cause mortality was not raised in those with isolated deficiency or idiopathic short stature (SMR 1.1, 95% CI 0.9 to 1.3). Deaths from circulatory and blood diseases were raised in all risk groups, and mortality was not related to dose [10]. In a cancer analysis of the same cohort, there was no clear raised cancer risk in people with growth failure without other major disease. Bone and bladder cancer incidence was raised in those without previous cancer, and Hodgkin lymphoma rose with longer follow-up [11]. In people with craniopharyngioma and growth hormone deficiency, a meta-analysis of 12 studies found lower tumor recurrence with growth hormone replacement (OR 0.56, 95% CI 0.41 to 0.77) [12]. The label lists neoplasms among its warnings [7].
Population: 24,232 [10] and 23,984 [11] people treated in 8 European countries, more than 400,000 patient-years [10]; children and adults with craniopharyngioma in 12 studies [12].
Sources: [10], [11], [12], [7]
Caveats: Observational, compared with general population rates or untreated patients. The cohorts were treated for diagnosed conditions, not as healthy adults.

Claims tested and not found

That growth hormone makes healthy athletes stronger. A systematic review of trials in fit young adults found strength and exercise capacity did not appear to improve [2], and an 8-week trial found no change in dead lift strength, VO2max or jump height [3].

Sources

Liu H, Bravata DM, Olkin I, et al. Systematic Review: The Safety and Efficacy of Growth Hormone in the Healthy Elderly. Annals of Internal Medicine. 2007. https://doi.org/10.7326/0003-4819-146-2-200701160-00005
Liu H, Bravata DM, Olkin I, et al. Systematic Review: The Effects of Growth Hormone on Athletic Performance. Annals of Internal Medicine. 2008. https://doi.org/10.7326/0003-4819-148-10-200805200-00215
Meinhardt U, Nelson AE, Hansen JL, et al. The Effects of Growth Hormone on Body Composition and Physical Performance in Recreational Athletes. Annals of Internal Medicine. 2010. https://doi.org/10.7326/0003-4819-152-9-201005040-00007
Sun F, Yang A, Jin Y, et al. Effects of low-dose growth hormone treatment on obesity: a meta-analysis of randomized controlled trials. Postgraduate Medicine. 2025. https://doi.org/10.1080/00325481.2025.2570106
Shah A, Patel NA, Udiaver R, et al. Human Growth Hormone as a Therapeutic Treatment Option in Orthopaedics: A Systematic Review of Dosing, Side Effects, and Clinical Outcomes. JBJS Reviews. 2026. https://doi.org/10.2106/jbjs.rvw.25.00194
Hazem A, Elamin MB, Bancos I, et al. Body composition and quality of life in adults treated with GH therapy: a systematic review and meta-analysis. European Journal of Endocrinology. 2012. https://doi.org/10.1530/EJE-11-0558
U.S. Food and Drug Administration. GENOTROPIN (somatropin) for injection, prescribing information. 2026. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ffebf88b-d257-4542-9808-74d9b7167765
Takala J, Ruokonen E, Webster NR, et al. Increased Mortality Associated with Growth Hormone Treatment in Critically Ill Adults. New England Journal of Medicine. 1999. https://doi.org/10.1056/NEJM199909093411102
Veenker CGH, Redzhebov BB, Hoeks SE, et al. Effects of growth hormone and anabolic steroids, in critically ill patients admitted to the intensive care unit: a systematic review and meta-analysis. Scientific Reports. 2025. https://doi.org/10.1038/s41598-025-20887-w
Sävendahl L, Cooke R, Tidblad A, et al. Long-term mortality after childhood growth hormone treatment: the SAGhE cohort study. The Lancet Diabetes & Endocrinology. 2020. https://doi.org/10.1016/S2213-8587(20)30163-7
Swerdlow AJ, Cooke R, Beckers D, et al. Cancer Risks in Patients Treated With Growth Hormone in Childhood: The SAGhE European Cohort Study. The Journal of Clinical Endocrinology & Metabolism. 2017. https://doi.org/10.1210/jc.2016-2046
Pan LS, Xiong YT, Ye ZC, et al. The effect of growth hormone replacement therapy on craniopharyngioma recurrence: a systematic review and meta-analysis. Pituitary. 2025. https://doi.org/10.1007/s11102-025-01581-6
Lasher AT, Liu K, Fitch MP, Sun LY. Isolating the direct effects of growth hormone on lifespan and metabolism in mice. Aging Cell. 2024. https://doi.org/10.1111/acel.14412
Sun LY, Spong A, Swindell WR, et al. Growth hormone-releasing hormone disruption extends lifespan and regulates response to caloric restriction in mice. eLife. 2013. https://doi.org/10.7554/elife.01098
Banks WA, Morley JE, Farr SA, et al. Effects of a growth hormone-releasing hormone antagonist on telomerase activity, oxidative stress, longevity, and aging in mice. Proceedings of the National Academy of Sciences of the United States of America. 2010. https://doi.org/10.1073/pnas.1016369107

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