Somatropin (HGH)

Key Benefits#

• Increases lean muscle mass and reduces body fat (particularly visceral)
• Restores growth hormone deficiency (FDA-approved)
• Improves bone mineral density
• Enhances exercise capacity and recovery
• Supports skin thickness and collagen synthesis
• Improves lipid profile in GHD patients
• Explored for anti-aging and cellular regeneration

Mechanism of Action#

Somatropin binds the growth hormone receptor (GHR) on hepatocytes and peripheral tissues, activating the JAK2-STAT5b signaling cascade. This drives hepatic IGF-1 production, the primary mediator of GH's anabolic effects. GH also directly stimulates lipolysis in adipocytes via hormone-sensitive lipase activation, increases protein synthesis in muscle, promotes chondrocyte proliferation for linear bone growth, and modulates glucose metabolism (insulin-antagonizing effect). IGF-1 mediates downstream myogenesis, nitrogen retention, and organ growth.

Dosing Protocols#

Side Effects#

• Fluid retention and edema (common, dose-dependent)
• Carpal tunnel syndrome
• Joint and muscle pain
• Insulin resistance and elevated blood glucose
• Acromegaly features with chronic supraphysiological dosing
• Potential tumor growth stimulation (IGF-1 elevation)
• Injection site reactions

Contraindications#

Active malignancy or prior cancer (IGF-1 promotion)Diabetic retinopathyAcute critical illnessClosed epiphyseal plates in pediatric patients (relative)Prader-Willi syndrome with obesity and respiratory compromise

Storage#

Lyophilized vials: store at 2-8 degrees C (refrigerator); do not freeze. Reconstituted: use within 21-28 days refrigerated. Protect from light. Pre-filled pens: refrigerate until use; can be kept at room temperature up to 28 days after first use depending on product.

1. 1.
   Once-weekly Lonapegsomatropin was Efficacious and Well Tolerated in Chinese Children with Growth Hormone Deficiency: Results from a Phase 3 Randomized Trial

   Ying Y, Wei H, Zhong Y, Li Y, Yang Y, Li G et al. · Hormone research in paediatrics · 2026PubMed Verified

2. 2.
   A helical peptide antagonist of the human growth hormone receptor

   Nahar K, Basu R, Ahmad A, Pettis J, Gamage U, Holub JM et al. · Endocrinology · 2026PubMed Verified

3. 3.
   Production of Biopharmaceutical Proteins from Scallop Hemocytes as a Bioreactor Using Improved Transfection Conditions

   Tsuda T, Sakaguchi A, Nagasawa K · Marine biotechnology (New York, N.Y.) · 2026PubMed Verified

4. 4.
   Synthesis of Arapaima gigas Growth Hormone (ag-GH) in HEK 293 Cells: Its Purification and Characterization via In Vivo Bioassay in Dwarf "Little" Mice

   Lima ER, Melo JCR, Bezerra FM, Suzuki MF, Nunes AP, Sevilhano TCDA et al. · Molecules (Basel, Switzerland) · 2026PubMed Verified

5. 5.
   Recombinant human growth hormone (rHGH) for muscle enhancement in knee osteoarthritis: protocol for a pilot, randomised placebo-controlled trial

   Shah A, Ravi B, Tomescu S, Catapano M, Burkhart TA, Whyne C et al. · BMJ open · 2026Clinical TrialPubMed Verified

6. 6.
   One IV HEDGES DNA vector administration encoding hGLA or hGH produces durable hGLA and hGH serum lvels in immunocompetent mice

   Ye A, Mack M, Ursu S, Chmura S, Steiner R, Heath T et al. · PloS one · 2025PubMed Verified

7. 7.
   Surgical Outcomes and Complications of Patients With Acromegaly in Qatar

   Ahmed A, A Elhadd T, Al Sada F, Dabbous Z, Belkhair S, Al Sulaiti G et al. · Cureus · 2025PubMed Verified

8. 8.
   Barriers to growth hormone access in pediatric patients at an academic medical center

   Parrish C, Baird D, Redd T, Moore RP, Choi L, Zuckerman AD et al. · American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists · 2025PubMed Verified

9. 9.
   Enhancement of Protein-Protein Interactions by Destabilizing Mutations Revealed by HDX-MS

   Hamuro Y, Armstrong A, Branson J, Wu SJ, Huang RY, Jacobs S · Biomolecules · 2025ReviewPubMed Verified

10. 10.
    Circulating growth hormone, cortisol and testosterone in relation to vitamin D status: influence of lower and upper body wingate anaerobic test in elite artistic gymnasts

    Mieszkowski J, Brzezińska P, Kochanowicz M, Niespodziński B, Grad R, Sawicki P et al. · BMC sports science, medicine & rehabilitation · 2025PubMed Verified

11. 11.
    Association of insulin-like growth factor 1 serum levels with early recovery and in-hospital complications after spinal fusion

    Bay A, Kim HJ, Durbas A, Colón L, Owusu-Sarpong S, Singleton Q et al. · Journal of neurosurgery. Spine · 2025PubMed Verified

12. 12.
    Human growth hormone-overexpressing adipose-derived stem cells enhance fibroblast activity and accelerate burn wound healing via ERK pathway therapeutic potential of ADSCs in burn wound repair

    Shao Y, Han M, Song G, Gao C · Regenerative therapy · 2025PubMed Verified

13. 13.
    Local Growth Hormone Facilitates Aging of the Colon Epithelial Microenvironment

    Chesnokova V, Zonis S, Ainsworth R, Apaydin T, Valencia CW, Greiner EC et al. · Aging cell · 2025PubMed Verified

14. 14.
    Acute effects of two different combined exercise modalities on executive function and circulating neurotrophic factors in young healthy adults

    Liao YH, Mündel T, Chen YC, Tsai SC, Wu KC, Chen MT et al. · European journal of applied physiology · 2026RCTPubMed Verified

15. 15.
    Insulin resistance reduction, intermittent fasting, and human growth hormone: secondary analysis of a randomized trial

    Horne BD, Anderson JL, May HT, Bair TL, Le VT, Iverson L et al. · npj metabolic health and disease · 2024PubMed Verified

16. 16.
    Human Fc C(H)2 domain modifies cholix transcytosis pathway to facilitate efficient oral therapeutic protein delivery

    Taverner A, Hunter T, Mackay J, Varenko V, Gridley K, Mrsny RJ · Journal of controlled release : official journal of the Controlled Release Society · 2025PubMed Verified

17. 17.
    The 20 kDa isoform of the human growth hormone variant alters adipose and muscle gene expression differently than human growth hormone

    Young JA, Bogart J, Buchman M, Duran-Ortiz S, Bell S, Kopchick JJ et al. · Journal of neuroendocrinology · 2025PubMed Verified

18. 18.
    Development of Competitive ELISAs Suitable for Detection of Recombinant Human Growth Hormone in Illegal Nutritional Supplements

    Karamonová L, Procházková B, Volný M, Nemeškalová A, Sýkora D, Kuchař M et al. · Journal of analytical methods in chemistry · 2025PubMed Verified

19. 19.
    Clinical and genetic analysis of ulnar-mammary syndrome caused by a novel TBX3 mutation in a Chinese boy

    Yang J, Yu H, Sun Y, Chen C, Li G, Xu C · Intractable & rare diseases research · 2025PubMed Verified

20. 20.
    Preclinical Safety

    Wolff RK, Blanchard JD · Journal of aerosol medicine and pulmonary drug delivery · 2025ReviewPubMed Verified

21. 21.
    Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy

    Lee T, Lee D, Jung E, Son M, Koo K, Choi J · PloS one · 2025PubMed Verified

22. 22.
    Evidence for Pituitary Repression of the Human Growth Hormone-Related Placental Lactogen Genes and a Role for P Sequences

    Cattini PA, Jin Y · International journal of molecular sciences · 2025ReviewPubMed Verified

23. 23.
    The TUITEK(®) patient support program improved caregiver-related behaviors on growth hormone treatment adherence

    Koledova E, Su PH, Chen YJ, Assefi A, Debicki M, Cooke D et al. · Frontiers in endocrinology · 2025PubMed Verified

24. 24.
    Excipient effect on phenol-induced precipitation of human growth hormone and bovine serum albumin

    Hjalte J, Börjesdotter AM, Diehl C, Ulvenlund S, Wahlgren M, Sjögren H · International journal of pharmaceutics · 2025PubMed Verified

25. 25.
    SRCAP-Related Floating-Harbor Syndrome

    Adam MP, Bick S, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A et al. · 1993ReviewPubMed Verified

26. 26.
    Children with Growth Hormone Deficiency Treated with Lonapegsomatropin Demonstrated Sustained Height Improvements for up to 6 Years: enliGHten Trial Final Results

    Maniatis AK, Thornton PS, Nadgir UM, Vlachopapadopoulou E, Malievskiy O, Aghajanova EM et al. · Hormone research in paediatrics · 2025PubMed Verified

27. 27.
    The Unfolding Story of Protein Misfolding Causing Alzheimer Disease in Recipients of Human Pituitary Growth Hormone

    Graber EG, Hosseini SMH, Wilson DM, Rogol AD · Journal of the Endocrine Society · 2025PubMed Verified

28. 28.
    Real-Time Detection of Human Growth Hormone Based on Nanoporous Anodic Alumina Interferometric Biosensor

    Cantons JM, Acosta LK, Formentin P, Ferré-Borrull J, Bachhuka A, Marsal LF · Sensors (Basel, Switzerland) · 2025PubMed Verified

29. 29.
    Weight loss-independent changes in human growth hormone during water-only fasting: a secondary evaluation of a randomized controlled trial

    Horne BD, Anderson JL, May HT, Bair TL, Le VT, Iverson L et al. · Frontiers in endocrinology · 2024RCTPubMed Verified

30. 30.
    Development of human growth hormone-treated chimeric mice with humanized livers for an evaluation model of drug-induced fatty liver disease

    Morioka S, Sanoh S, Ishida Y, Furukawa S, Ogawa Y, Kotake Y et al. · Archives of toxicology · 2025PubMed Verified

31. 31.
    Development of a Sensitive Quantum Dot-Linked Immunoassay for the Multiplex Detection of Biochemical Markers in a Microvolumeric Format

    Kalvaityte U, Bagdonas E, Kirdaite G, Kausaite-Minkstimiene A, Uzieliene I, Ramanaviciene A et al. · International journal of nanomedicine · 2025PubMed Verified

32. 32.
    Evidence Suggesting That Alzheimer's Disease May Be a Transmissible Disorder

    Saw G, Yi LX, Tan EK, Zhou ZD · International journal of molecular sciences · 2025PubMed Verified

33. 33.
    Diastolic Dysfunction with Normal Ejection Fraction and Reduced Heart Rate in Mice Expressing Human Growth Hormone and Displaying Signs of Growth Hormone Insufficiency

    Jin Y, Xiang B, Dolinsky VW, Kardami E, Cattini PA · International journal of molecular sciences · 2024PubMed Verified

34. 34.
    Effects of recombinant human growth hormone in severe neurosurgical patients: A single center, retrospective study

    Liao X, Huang H, Qiu B, Chen J, Zhang A, Liang H et al. · PloS one · 2025PubMed Verified

35. 35.
    Human GH Use By Athletes With Short Stature Without GH Deficiency: Therapeutic Use Exemptions

    Allen DB, Vernec A, Branco P, Cappa M, Horikawa R, Banon T et al. · The Journal of clinical endocrinology and metabolism · 2025ReviewPubMed Verified

36. 36.
    SpyFixer enables efficient site-specific immobilization for protein-protein interaction analysis and antibody purification

    Xiang Y, Lao Z, Lin Z, Yang X · International journal of biological macromolecules · 2025PubMed Verified

37. 37.
    Abdominal Hypertrophy Syndrome: Characteristics and Potential Pathophysiology

    Suslin IA, Efimenko IV, Castrellon R, Husain TM · Cureus · 2024ReviewPubMed Verified

38. 38.
    A retrospective study of recombinant human growth hormone in the treatment of school-aged pediatric patients with idiopathic short stature

    Chen Y, Li YH, Zhang XR · Medicine · 2024PubMed Verified

39. 39.
    Use of connected injection device has a positive effect on catch-up growth in patients with growth disorders treated with growth hormone therapy

    de Arriba A, van Dommelen P, Savage MO · Frontiers in endocrinology · 2024PubMed Verified

40. 40.
    Somatrem

    2006ReviewPubMed Verified

41. 41.
    Somatropin

    2006ReviewPubMed Verified

42. 42.
    Interleukin-17A (IL-17A) is involved in antibody specificity to conformational epitopes

    Ottobre M, Van Snick J, Aparicio JL · Biochemical and biophysical research communications · 2024PubMed Verified

43. 43.
    Preferences for Injection Device Settings and the Association with Adherence to Growth Hormone Treatment in Patient with Growth Disorders

    van Dommelen P, Rivera-Romero O, Arnaud L, Zucchiatti C, Koledova E · Studies in health technology and informatics · 2024PubMed Verified

44. 44.
    Healthcare professionals' perspectives towards the digitalisation of paediatric growth hormone therapies: expert panels in Italy and Korea

    Rivera Romero O, Chae HW, Faienza MF, Vergani E, Cheon CK, Di Mase R et al. · Frontiers in endocrinology · 2024PubMed Verified

45. 45.
    The growzen™ buddy smartphone app to improve adherence in patients receiving recombinant human growth hormone therapy: a retrospective observational study in Argentina

    van Dommelen P, Arnaud L, Assefi AR, Crespo ML, Debicki M, Michelis F et al. · Frontiers in endocrinology · 2024PubMed Verified

46. 46.
    Detection of the GH analog somatrogon in sports drug testing: Immunological approaches and LC-HRMS/MS

    Walpurgis K, Thomas A, Sato M, Okano M, Geyer H, Thevis M · Drug testing and analysis · 2025PubMed Verified

47. 47.
    Preparation and characterization of the injectable pH- and temperature-sensitive pentablock hydrogel containing human growth hormone-loaded chitosan nanoparticles via electrospraying

    Huynh DP, Tran TA, Nguyen TTH, Nguyen VVL · Journal of biomaterials science. Polymer edition · 2024PubMed Verified

48. 48.
    The protection role of human growth hormone on skin cells following ultraviolet B exposure

    Taghizadeh B, Moradi R, Mirzavi F, Barati M, Soleimani A, Jaafari MR et al. · Journal of photochemistry and photobiology. B, Biology · 2024PubMed Verified

49. 49.
    Increased capacity to maintain glucose homeostasis in a transgenic mouse expressing human but not mouse growth hormone with developing high-fat diet-related insulin resistance, hepatic steatosis and adipose dysfunction

    Jin Y, Jarmasz JS, Sultana S, Cordero-Monroy L, Taylor CG, Zahradka P et al. · Journal of molecular endocrinology · 2024PubMed Verified

50. 50.
    Biological Variation Data in Triathletes for Metabolism and Growth-Related Biomarkers Included in the Athlete Biological Passport

    Moreno-Parro I, Diaz-Garzon J, Aarsand AK, Sandberg S, Aikin R, Equey T et al. · Clinical chemistry · 2024PubMed Verified