Growth Factors

HGH (Somatropin)

Evidence: strong_human

Mechanism of Action

Human Growth Hormone (somatropin) is a 191-amino acid single-chain polypeptide produced by anterior pituitary somatotrophs. It binds the GH receptor (GHR), activating JAK2-STAT5 signaling and MAP kinase pathways. Systemically, HGH upregulates hepatic IGF-1 production, which mediates most of its anabolic effects through IGF-1R/PI3K/Akt/mTOR-driven protein synthesis. Direct GH effects include lipolysis activation, insulin antagonism, chondrocyte/osteoblast stimulation, and enhanced collagen synthesis. Effects are divided into direct (lipolysis, insulin antagonism) and indirect (IGF-1-mediated growth and anabolism).

Dosing Protocol

Standard: Research indicates 1-2 IU daily for anti-aging and general optimization. 2-4 IU daily for body composition. 4-8+ IU daily in clinical GH deficiency (physician-supervised only).

Maintenance: Research indicates 1-2 IU daily for long-term anti-aging protocols, titrated to maintain IGF-1 within the upper normal age-adjusted range (IGF-1 SDS between 0 and +2).

Administration: subcutaneousintramuscular

Timing: Bedtime injection (mimics natural nocturnal GH surge) or morning fasted. Split dosing (AM + pre-bed) for higher doses. Always on empty stomach — carbohydrates blunt GH action.

Duration: Continuous use is common in anti-aging protocols. 6-12 month minimum for full benefits. Clinical GHD treatment is typically lifelong.

Notes

HGH is the most well-studied compound in this database with decades of clinical data. The landmark 1990 Rudman NEJM study showed significant body composition improvements in men over 60 (8.8% lean mass increase, 14.4% fat decrease). However, side effects at higher doses are common. Modern anti-aging protocols use lower doses (1-2 IU) with IGF-1 monitoring to stay within physiological range. Starting low (0.1-0.2 mg/day) and titrating based on IGF-1 levels minimizes side effects. GH secretagogues (CJC-1295 + Ipamorelin) are often preferred over exogenous GH because they preserve pulsatile release patterns and are less expensive. HGH is a controlled substance in the US (Schedule III) — legal only with a prescription for diagnosed GH deficiency.

Stacking

  • CJC-1295/Ipamorelin (use one or the other — not GHS + exogenous GH)
  • BPC-157
  • TB-500

Interactions

  • Insulin [HIGH] — GH directly antagonizes insulin; diabetogenic at higher doses. Monitor glucose closely.
  • Thyroid hormones [MEDIUM] — GH increases T4-to-T3 conversion; may unmask subclinical hypothyroidism.
  • Glucocorticoids [MEDIUM] — Glucocorticoids blunt GH effects and suppress GH secretion.
  • Estrogen (oral) [MEDIUM] — Oral estrogen reduces hepatic IGF-1 production, diminishing GH efficacy.

Contraindications

  • Active cancer or active tumors
  • Diabetic retinopathy (proliferative)
  • Acute critical illness
  • Closed epiphyses with active acromegaly features
  • Prader-Willi syndrome with severe obesity/respiratory impairment
  • Pregnancy and breastfeeding

Side Effects

  • Water retention/edema
  • Joint pain (arthralgia)
  • Carpal tunnel syndrome
  • Insulin resistance/elevated blood glucose
  • Gynecomastia
  • Numbness/tingling
  • Headache
  • Potential organ growth at high doses
  • Jaw/hand growth with chronic supraphysiological use

Key Papers

  • 10.1056/NEJM199007053230101
  • 10.3389/fendo.2020.619173

Source Quality

Pharmaceutical-grade only (Genotropin, Norditropin, Humatrope, Omnitrope, etc.). Generic biosimilars available. NEVER use 'underground' or unverified HGH — counterfeiting is rampant. Serum IGF-1 testing validates authentic product.

Disclaimer: This information is for educational purposes only and is not medical advice. BioAccelera Labs does not diagnose, treat, or prescribe. Consult a licensed healthcare provider before using any compound.

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