Every GH secretagogue covered in the secretagogues post works by pushing your pituitary harder. Human growth hormone — the actual 191-amino-acid peptide — bypasses that mechanism entirely. You inject it; the dose is whatever you put in the syringe. No pituitary ceiling, no age-dependent ceiling. That’s the appeal, and the reason the safety picture is sharper here than for any secretagogue.
What it is
Recombinant somatropin is bioidentical to pituitary-produced growth hormone. It drives lipolysis via hormone-sensitive lipase, upregulates IGF-1 in the liver, promotes collagen synthesis, and produces pronounced effects on skin texture, tissue density, and recovery. GH secretion declines roughly 85% from puberty peak by age 55 — secretagogues can amplify a barely-firing pituitary pulse; exogenous HGH creates the baseline independently.
Pharmaceutical products (Norditropin, Genotropin, Omnitrope) are FDA-approved for growth hormone deficiency; anti-aging and body composition use is off-label. Generic HGH from Chinese and Indian manufacturers is widely used; batch-to-batch consistency varies. The vial must hold vacuum and the reconstituted solution must be clear — cloudy means denatured, discard it.
What the research actually shows
FDA Serostim data establishes the dose-response curve: meaningful fat mass reduction starts around 4 mg (12 IU) daily; lean tissue hyperplasia begins around 6 mg (18 IU). Above 6 mg, additional HGH does not produce greater anabolic output — hepatic IGF-1 production is the ceiling, not the HGH dose. The FDA document classifies more than 18 IU daily as an overdose threshold.
Tesamorelinand HGH are the only two compounds with clinical evidence for visceral fat reduction. The “GH gut” attribution is wrong — the Serostim research showed GH reducing visceral distension, not causing it. Bubble gut is driven by insulin, oral androgens, and poor TVA control. Use SubQ; IM triggers a cytokine response that wastes part of the dose with no benefit over SubQ on IGF-1 output.
How people dose it
HGH is measured in International Units (IU), not micrograms. The WHO standard: 1 IU = 0.33 mg somatropin; 1 mg = 3 IU. A 10 IU vial holds approximately 3.33 mg. Standard reconstitution: 1 mL bacteriostatic water → 10 IU/mL. On a U-100 insulin syringe, 0.1 mL (10 units on the barrel) = 1 IU.
- Low (2–3 IU/day):20–30 units on a U-100 syringe. Anti-aging, recovery, sleep quality; equivalent to an optimized secretagogue stack.
- Medium (4–6 IU/day):40–60 units, once or twice daily. Body composition and fat loss; where FDA data shows meaningful fat mass reduction.
- High (7–9 IU/day):70–90 units, split two to three times daily. Bodybuilder range; water retention and blood glucose management become priority concerns.
- Aggressive (10–17 IU/day): Split two to four times daily. FDA overdose threshold is above 18 IU (6 mg); diminishing anabolic returns are documented above that level. Requires IGF-1 and glucose monitoring.
Timing: for fat loss, inject 60–90 minutes before fasted cardio (SubQ peak at 90–120 minutes). For muscle and recovery, before bed aligns with the natural nocturnal GH peak. For both goals, split morning and night. Daily dosing produces optimal IGF-1 area-under-the-curve.
What it stacks well with
The CJC-1295 + Ipamorelin blend layers cleanly on top: HGH provides a controlled baseline; the secretagogue maintains pulsatile endogenous signaling. For joint pain and connective tissue repair — which HGH can exacerbate at higher doses — BPC-157 and TB-500 are standard additions. BPC-157 upregulates GH receptor density in tendon fibroblasts, synergizing with HGH for tendon repair.
The honest caveats
- Cancer caveat — sharper than for secretagogues.HGH does not cause cancer, but it promotes angiogenesis and drives IGF-1 elevation, which can accelerate progression of an existing undetected tumor. Get a full-body MRI and cancer marker panel before starting meaningful doses — especially if you are over 40.
- Insulin resistance is diet-driven, not HGH-driven.HGH causes lipolysis, releasing free fatty acids that can impair insulin receptor function. Monitor fasting glucose weekly at any dose above 4 IU. Berberine (500–2,000 mg/day) is the preferred management tool — it activates AMPK without suppressing IGF-1. Metformin is counterproductive: 1,000 mg daily can drop IGF-1 to roughly 80 ng/dL. Use only transiently if glucose is genuinely elevated, then switch to Berberine.
- Water retention in the first 4–8 weeks.Manage with adequate hydration and, if needed, Dandelion Root (500–4,000 mg/day). Usually attenuates after two months.
- Carpal tunnel and joint pain at higher doses. Dose-dependent. Reduce the dose and use a wrist brace if tingling develops. Pause until resolved. Known dose-limiting side effect at 7 IU+.
- WADA prohibited; prescription-only. Standard workplace drug screens do not test for HGH; risk is sport-specific.
- Generic quality verification. Vial must hold vacuum; no vacuum means likely repackaging. Solution must be clear — cloudy means denatured. Third-party testing (Janoshik) for purity above 97% before committing to a source.
The bottom line
Secretagogues are cheaper for equivalent output at the 2–3 IU range. Above 4 IU equivalent output, no secretagogue can keep up — the pituitary is the ceiling. For users who need to go higher, or whose pituitary has declined to the point secretagogues barely move the needle, exogenous HGH is the only tool that works.
Read the GH secretagogues post for the full HGH-vs-secretagogue comparison. For dosing math on the most popular secretagogue alternative, use the CJC-1295 + Ipamorelin calculator. For protocol context — glucose monitoring, Berberine dosing, cycle structuring — see the free Peptide Guide.