HGH
Also known as: Somatropin, Somatotropin, rhGH, Recombinant Human Growth Hormone
Human Growth Hormone | Somatropin
Overview
Human Growth Hormone (HGH/Somatropin) is a 191-amino acid polypeptide hormone FDA-approved for pediatric and adult growth hormone deficiency, HIV-associated wasting, and other conditions. It provides both direct and indirect (IGF-1 mediated) anabolic effects.
Key benefits
- Improved body composition (increased lean mass, decreased fat)
- Enhanced bone mineral density
- Improved lipid profile
- Increased exercise capacity
- Better quality of life and mood
- Skin, hair, and nail improvements
- Enhanced recovery and healing
Mechanism of action
Binds to GH receptors on target tissues, triggering JAK2-STAT5 signaling pathway. Direct effects include lipolysis, protein synthesis, and metabolic regulation. Indirect effects via IGF-1 promote growth and anabolism. Half-life ~3 hours subcutaneously.
Molecular data
- Type
- Single-chain polypeptide with two disulfide bridges
- Half-life
- 3-4 hours (SC), 20-30 minutes (IV)
Indications
What the research community uses this compound for, with self-reported effectiveness.
Growth Hormone Deficiency
Pediatric GH Deficiency
Most effectiveFDA-approved for idiopathic and organic causes, Turner syndrome, Prader-Willi syndrome, SGA, Noonan syndrome, SHOX deficiency.
Adult GH Deficiency
Most effectiveFDA-approved for childhood-onset or adult-onset causes (pituitary tumors, surgery, radiation, trauma).
HIV-Associated Wasting
EffectiveFDA-approved to increase lean body mass and body weight in cachexia.
Body Composition
Fat Loss
EffectiveSignificant fat loss especially abdominal/visceral fat over 1-3 months.
Lean Mass
EffectiveIncreased muscle mass and improved body composition.
Recovery Enhancement
EffectiveEnhanced exercise recovery and tissue healing.
Anti-Aging
Skin and Hair Quality
ModerateImproved skin elasticity, texture, and hair/nail growth.
Energy and Well-being
ModerateImproved energy, sleep, and quality of life.
Dosing protocols
Common protocols by delivery method. Adjust the curve below to model accumulation in your own cycle.
Injectable
Subcutaneous injection is the only effective route. Morning fasted injection maximizes fat-burning potential; evening mimics natural nocturnal GH pulse.
| Protocol | Dose | Frequency | Route / duration |
|---|---|---|---|
| Medical GHD (Starting) | 0.15-0.3mg/day (0.5-1 IU) | Once daily | SubQ |
| Medical GHD (Maintenance) | 0.4-0.8mg/day (1.2-2.4 IU) | Once daily | SubQ |
| Anti-Aging/Wellness | 1-2 IU/day (0.33-0.67mg) | Once daily | SubQ |
| Body Recomposition | 2-4 IU/day (0.67-1.33mg) | Once or twice daily | SubQ |
| Performance (Higher Risk) | 4-8 IU/day (1.33-2.67mg) | Split twice daily | SubQ |
Preparation
You will need
- HGH lyophilized powder vial (typically 10 IU or 36 IU)
- Bacteriostatic water for injection
- Insulin syringes (29-31 gauge)
- Alcohol prep pads
Steps
- Allow vial to reach room temperature (15-20 minutes)
- Clean rubber stoppers with alcohol swab
- Determine reconstitution volume (typical: 1mL BAC water per 10 IU)
- Draw bacteriostatic water slowly, removing air bubbles
- Insert needle at angle, aiming stream at vial wall - not directly on powder
- Inject water slowly down inside wall, drop by drop
- Remove needle and gently swirl in circular motion - never shake
- Allow to sit if cloudy, then swirl again until crystal clear
- Solution must be crystal clear; discard if cloudy or contains particles
- Label with reconstitution date and concentration
- Store refrigerated at 2-8°C; use within 14-28 days
Work out the water volume and syringe units in the reconstitution calculator →
Interactions
Pairwise interactions with other compounds you might be cycling — the same data behind the cycle builder's safety check.
Insulin
MonitorHGH decreases insulin sensitivity; may require increased insulin doses in diabetics.
IGF-1/IGF-1 LR3
MonitorSynergistic but caution: enhanced effects with increased hypoglycemia and side effect risk.
Thyroid Hormones (T3/T4)
MonitorIncreases T4 to T3 conversion; unmasks hypothyroidism in 36-47% of patients.
Cortisol/Hydrocortisone
MonitorCan unmask cortisol deficiency; replacement should precede HGH.
Metformin
MonitorMay manage insulin resistance; may reduce IGF-1 levels.
CJC-1295
SynergisticGHRH analog can enhance effects though may be redundant with exogenous HGH.
Ipamorelin
SynergisticGhrelin mimetic works via different pathway.
GHRP-6/GHRP-2
SynergisticEnhances natural pulsatile release.
Testosterone
SynergisticCommonly combined in hormone replacement therapy.
Semaglutide/Tirzepatide
CompatibleGLP-1 agonists help manage insulin resistance during HGH therapy.
Timeline
Typical week-by-week effects reported in clinical and observational data.
- Week 1-2
Improved sleep quality, increased energy, possible water retention and joint stiffness
- Week 2-4
Enhanced exercise recovery, skin improvement, possible carpal tunnel symptoms
- Month 1-2
Noticeable fat loss (especially abdominal), improved skin elasticity and texture
- Month 2-3
Continued fat loss, lean mass improvements, hair/nail growth, reduced recovery time
- Month 3-6
Significant body composition changes, improved bone density, sustained energy/well-being
- Long-term
Maintained benefits; effects diminish weeks-months after discontinuation
Safety
Reported adverse effects, contraindications, and what to monitor on cycle.
Common side effects
- Water retention and fluid accumulation
- Joint pain and stiffness
- Carpal tunnel syndrome (usually resolves with dose reduction)
- Headaches
- Numbness/tingling in hands
Stop signs — stop and seek advice
- Severe or worsening carpal tunnel symptoms
- Signs of diabetes (increased thirst, frequent urination, blurred vision)
- Severe edema (facial, hand, or feet swelling)
- Severe joint/muscle pain unresponsive to dose reduction
- New lumps, masses, or rapidly growing moles
- Severe headaches or vision changes
- Signs of allergic reaction
- Gynecomastia (breast tissue growth in males)
- Hypothyroid symptoms (fatigue, weight gain, cold intolerance)
Contraindications
- Active cancer (may accelerate tumor growth)
- Acute critical illness (increased mortality in ICU patients)
- Closed epiphyses in children (for growth promotion)
- Pregnancy/breastfeeding
Monitoring
- Blood glucose - HGH causes insulin resistance and can unmask diabetes
- Thyroid function - can unmask hypothyroidism; may require T4 supplementation
- IGF-1 levels to assess dosing adequacy
- Intracranial pressure if headaches develop
Quality checks
What a legitimate product looks like, what should give pause, and what should make you stop.
Good signs
- White to off-white lyophilized powder or solid cake (not liquid/collapsed)
- Crystal clear reconstituted solution with no particles
- Intact vacuum in sealed vial (resistance when inserting needle)
- Pharmaceutical grade with certificate of analysis (Genotropin, Norditropin, Humatrope preferred)
Warning signs
- Generic/underground lab products have highly variable quality and potency
- Common counterfeits exist; third-party testing recommended
Stop signs — don't use
- Cloudy, discolored, or particles visible indicates degradation
- Powder appears melted or stuck to vial (improper storage)
- Yellow/brown coloring
Recent research
Newer papers and trial readouts on file for this compound, with source and date.
2024 · Journal of Endocrinological Investigation
A 2024 Update on Growth Hormone Deficiency Syndrome in Adults: From Guidelines to Real Life
Comprehensive update on diagnosing and treating adult GHD, emphasizing individualized evaluation of risks and benefits. Reviewed evidence up to August 2024.
2024 · Drug Design, Development and Therapy
Developments in the Management of Growth Hormone Deficiency: Clinical Utility of Somapacitan
Somapacitan (Sogroya) is the first long-acting GH approved for adult GHD in the US, Europe, and Japan, enabling once-weekly dosing convenience.
References
Primary literature and clinical-trial data informing this entry.
Long-term Safety of Growth Hormone in Adults With Growth Hormone Deficiency: Overview of 15,809 GH-Treated Patients
Stochholm K, Kiess W, Gianetti E, et al. · Journal of Clinical Endocrinology & Metabolism · 2022
15,809 patients from the KIMS database, mean 5.3 years follow-up. Adverse events in 51.2% of patients, treatment-related in 18.8%. No correlation between GH dose and adverse event rate. Supports long-term safety of GH replacement in adults with GHD.
Efficacy and Safety of Growth Hormone Treatment in Adults with Growth Hormone Deficiency: A Systematic Review of Studies on Morbidity
Defined a, Sääf M, et al. · Clinical Endocrinology · 2014
Systematic review demonstrating positive effects of GH treatment on cardiovascular disease and fracture risk, improvements in body composition, muscle strength, quality of life, bone mass/density, and lipoprotein patterns.
Cardiovascular Risk in Growth Hormone Deficiency: Beneficial Effects of Growth Hormone Replacement Therapy
Gazzaruso C, Gola M, Karamouzis I, et al. · Endocrine · 2016
GH deficiency is associated with several cardiovascular risk factors that significantly increase cardiovascular morbidity and mortality. GH replacement improves cardiovascular risk factors.
Unmasking of Central Hypothyroidism Following Growth Hormone Replacement in Adult Hypopituitary Patients
Agha A, Walker D, Perry L, et al. · Clinical Endocrinology · 2007
In 84 apparently euthyroid patients, 30 (36%) developed hypothyroidism requiring T4 therapy after starting GH. Highest risk in patients with organic pituitary disease or multiple pituitary hormone deficiencies.
Last updated . How this page was sourced is described in the methodology.