HGH / Somatropin Guide
Human Growth Hormone: Dosage, Brands, IGF-1 Monitoring & Peptide Alternatives
Recombinant human growth hormone (somatropin) is the gold standard for treating diagnosed GH deficiency and is widely prescribed off-label at longevity clinics. This guide covers everything from mechanism and FDA-approved brands to dosage protocols, IGF-1 monitoring, and when peptide therapy is a better choice.
What is Somatropin (rHGH)?
Somatropin is recombinant human growth hormone (rHGH) — a 191 amino acid protein identical in sequence and structure to endogenous pituitary GH. It is produced via recombinant DNA technology in yeast or mammalian cell cultures, resulting in a biologically identical molecule to what the pituitary gland secretes naturally.
The FDA has approved somatropin for multiple indications: adult and pediatric growth hormone deficiency, Turner syndrome, HIV-associated wasting (as Serostim), short bowel syndrome, and Prader-Willi syndrome. Off-label use for anti-aging, longevity, and body composition is widespread at private longevity clinics — it is legal for physicians to prescribe off-label, though it is not legal to market for performance enhancement.
Mechanism: Somatropin exerts both direct effects (lipolysis, reduced glucose uptake, protein synthesis stimulation) and indirect effects via IGF-1 produced by the liver in response to GH signaling. IGF-1 then acts on GH receptors throughout the body to drive anabolic, anti-catabolic, and mitogenic effects.
FDA-Approved Brands Compared
| Brand | Manufacturer | Type | Delivery Device | Est. US Cost/Month |
|---|---|---|---|---|
| Norditropin | Novo Nordisk | Originator | FlexPro pen (prefilled) | $1,200–$2,000+ |
| Humatrope | Eli Lilly | Originator | HumatroPen cartridge | $1,000–$1,800+ |
| Genotropin | Pfizer | Originator | GoQuick pen / MiniQuick | $1,100–$1,900+ |
| Omnitrope | Sandoz | Biosimilar (FDA-approved) | Pen 5 / Pen 10 | $800–$1,400 |
| Serostim | EMD Serono | HIV wasting approved | Vial + syringe | Varies (HIV indication) |
Dosage Ranges by Use Case
Clinical GH Deficiency (Adult)
0.1–0.3mg/day (0.3–0.9 IU/day). Dose is titrated based on IGF-1 response and side effects. Start low and adjust every 1–2 months. Goal is to restore IGF-1 to mid-normal range for age.
Anti-Aging / Longevity
0.5–1 IU/day (~0.17–0.33mg). Low-dose protocol popular at longevity clinics for individuals with low-normal IGF-1. Emphasizes quality-of-life benefits: energy, sleep, body composition, skin quality.
Body Composition (Off-Label)
2–4 IU/day. Common in performance-focused protocols. Higher IGF-1 elevation but substantially increased risk of side effects: carpal tunnel, water retention, joint pain, insulin resistance.
Administration Timing
Daily SQ injection into abdomen or thigh, rotating sites. Morning dosing supports lipolysis (fat burning) during daytime activity; pre-sleep dosing maximizes the natural GH pulse amplitude. Protocol depends on individual goals.
HGH vs. Peptide Therapy: When to Choose Each
For many patients — particularly those without a formal GH deficiency diagnosis — peptide therapy (CJC-1295 + ipamorelin, or sermorelin) is the preferred starting point. These GHRH/GHRP peptides stimulate the pituitary to produce its own GH, preserving the natural feedback loop and avoiding the axis suppression that comes with exogenous HGH.
- •Choose HGH when: Diagnosed GH deficiency (low IGF-1 + confirmatory stimulation test), older patients with depleted pituitary reserve who no longer respond adequately to secretagogues, or when maximum IGF-1 elevation is needed.
- •Choose peptide therapy when: IGF-1 is low-normal but pituitary reserve exists, younger patients, budget-conscious individuals ($100–300/month compounded vs. $800–2,000+ for pharma HGH), and those who prefer a more physiological approach.
- •IGF-1 monitoring is essential in both cases: Keep within the normal age-adjusted range. Elevated IGF-1 is theoretically associated with increased cancer risk — the same principle applies whether GH comes from injections or pituitary stimulation.
Frequently Asked Questions
What is the difference between HGH brands like Norditropin, Humatrope, and Genotropin?
All are recombinant somatropin — 191 amino acid GH identical to endogenous pituitary GH. Differences are primarily in pen delivery device, storage, and cost. Omnitrope is an FDA-approved biosimilar at lower cost. Clinically, all brands are bioequivalent.
What HGH dose is used for anti-aging at longevity clinics?
Longevity clinics typically prescribe 0.5–1 IU/day (~0.17–0.33mg) — much lower than clinical deficiency replacement and far below bodybuilding doses. The goal is to support IGF-1 at the upper end of normal for age. IGF-1 monitoring every 3–6 months is essential.
Is HGH peptide therapy safer than somatropin?
Peptide therapy (sermorelin, CJC-1295 + ipamorelin) preserves the natural pituitary feedback loop, so the body cannot overshoot to supraphysiologic IGF-1 levels. This is a theoretical safety advantage over direct HGH. Cost is also substantially lower. However, peptide therapy cannot fully replace HGH for patients with diagnosed deficiency or depleted pituitary reserve.