Somatropin (rHGH)
Recombinant human growth hormone bioidentical to endogenous 191-aa GH. FDA-approved for GH deficiency, HIV wasting, Turner syndrome, and Prader-Willi syndrome. Stimulates IGF-1, lipolysis, and lean mass accrual directly via GHR receptors.
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Compound Profile
Somatropin (rHGH)
Key Data
Research reference only
Research Focus
Preclinical data
⚠ Research & Educational Use Only. Somatropin (rHGH) is a research chemical documented here for scientific education. All information references peer-reviewed literature and preclinical/clinical study data. Not for human consumption. Not medical advice. Consult a licensed researcher or healthcare professional before any laboratory use.
- Directly activates GH receptors (GHR) without relying on endogenous GH secretion — bypasses pituitary limitations
- Stimulates liver IGF-1 production, driving anabolic and tissue repair effects downstream
- Reduces visceral adiposity in GH-deficient adults; approved for HIV-associated wasting (Serostim)
- Somatropin (rHGH) is not FDA-approved for human use. Prescription drug. Schedule III controlled substance in the US. FDA-approved for specific indications only. Illegal for anti-aging or performance use without a prescription.
Research At a Glance
- Directly activates GH receptors (GHR) without relying on endogenous GH secretion — bypasses pituitary limitations
- Stimulates liver IGF-1 production, driving anabolic and tissue repair effects downstream
- Reduces visceral adiposity in GH-deficient adults; approved for HIV-associated wasting (Serostim)
- Increases lean body mass and reduces fat mass in hypopituitary and GH-deficient patients
In Plain English
Simple summarySomatropin is recombinant human growth hormone -- identical in sequence to the 191-amino acid GH your pituitary naturally produces, synthesized using recombinant DNA technology. It's not a peptide in the same sense as most compounds on this site; it's a full-sized protein hormone. But it's the reference compound against which every GH secretagogue (CJC-1295, ipamorelin, sermorelin, tesamorelin) is measured. Understanding what exogenous rHGH actually does in adults -- and what it doesn't -- is essential context for understanding the entire GH-secretagogue category. The clinical record is substantial: rHGH has been FDA-approved since 1985 for GH deficiency and has been used in adult GH deficiency, Turner syndrome, Prader-Willi, short bowel syndrome, and HIV wasting.
- Directly activates GH receptors (GHR) without relying on endogenous GH secretion — bypasses pituitary limitations
- Stimulates liver IGF-1 production, driving anabolic and tissue repair effects downstream
- Reduces visceral adiposity in GH-deficient adults; approved for HIV-associated wasting (Serostim)
The full scientific detail, mechanisms, citations, and dosing data, follows below.
What is Somatropin (rHGH)?
Tap any underlined term for an instant definition.
Somatropin is recombinant human growth hormone (rHGH), a 191-amino acid single-chain polypeptide that is bioidentical to the endogenous GH produced by somatotroph cells of the anterior pituitary gland. It is produced via recombinant DNA technology in E. coli or mammalian cell expression systems.
Unlike growth hormone secretagogues (GHSPs like ipamorelin, CJC-1295, or GHRP-2), which stimulate the pituitary to release endogenous GH, somatropin acts directly on peripheral GH receptors (GHR) throughout the body. This means it bypasses pituitary regulation entirely and can achieve pharmacological GH levels regardless of the patient's pituitary function.
Key mechanisms include
- **Direct GHR activation** → stimulates JAK2/STAT5 signaling in hepatocytes → IGF-1 production
- **Lipolysis**: GH promotes lipase activity in adipocytes, directly mobilizing triglycerides
- **Protein anabolism**: GH stimulates amino acid uptake and protein synthesis in muscle
- **Anti-insulin effect**: GH opposes insulin signaling at skeletal muscle → glucose sparing for the brain
FDA-approved uses include: Adult and pediatric GH deficiency, Turner syndrome, Prader-Willi syndrome, small-for-gestational-age (SGA) children, chronic kidney disease, HIV-associated wasting (Serostim), and short bowel syndrome (Zorbtive).
The relationship between somatropin and the various GHSPs documented in this database is that GHSPs are often preferred in research settings because they work with the body's natural pulsatile GH rhythm and feedback loops, whereas exogenous rHGH suppresses endogenous GH axis activity through GHRH/somatostatin feedback.
By the Numbers
Key Research Benefits
Documented effects observed in preclinical and clinical studies on Somatropin (rHGH). See all Growth Hormone Secretagogues peptides for comparison.
Side Effects & Risks
Adverse effects reported in the research literature. All data sourced from preclinical and clinical study reports. View all peptides' side effects →
Dosing Data from the Literature
Doses referenced below are sourced from published preclinical and clinical studies. Use the peptide dose calculator to convert these values to injection volume.
In FDA-approved clinical settings, GH deficiency replacement typically uses 0.2-0.6 mg/day (individualized by IGF-1 targeting). Research protocols for body composition use 1-3 IU/day subcutaneously.
FDA-approved GHD replacement: 0.2-0.4 mg/day in adults (titrated to IGF-1) Research anti-aging / body composition: 1-2 IU/day Anti-wasting (HIV): up to 6 mg/day (Serostim approval) Administration: Subcutaneous injection, typically in the evening to align with natural GH peak
Administration in Research Settings
Standard reconstitution and administration methodology for laboratory research use.
Reconstituted with bacteriostatic water. Administered subcutaneously (abdomen, thigh). Evening injection aligns with the natural nocturnal GH peak. Must be refrigerated after reconstitution.
What the research doesn't show
rHGH side effects in adults are real and dose-dependent: fluid retention, carpal tunnel, joint pain, and at higher doses, insulin resistance. The concern about IGF-1-driven cancer promotion at supraphysiological doses is not resolved. Most anti-aging uses are at lower physiological replacement doses, but the long-term safety of even low-dose rHGH in adults without GHD hasn't been definitively studied.
Medical Expert Videos
Physicians, researchers, and pharmacologists explain Somatropin (rHGH), covering mechanisms of action, clinical context, and study findings.
Videos sourced from YouTube search. KnowYourPeptide does not endorse any individual creator. For research education only.
The Bottom Line
Somatropin (rHGH) has a growing body of preclinical evidence and a well-characterised safety profile in research settings. The most-studied application is: directly activates gh receptors (ghr) without relying on endogenous gh secretion — bypasses pituitary limitations.
The most commonly reported side effect in research subjects is carpal tunnel syndrome and peripheral edema at supraphysiological doses. It is a research chemical, not approved for human use.
Frequently Asked Questions
Explore Further
Quick Reference
How It Compares
CJC-1295 + ipamorelin is the most popular secretagogue alternative -- it stimulates your own pituitary to produce GH rather than replacing it externally. The key difference is physiological pulsatility: secretagogues preserve the natural GH pulse pattern while rHGH creates a steady supraphysiological level. Most anti-aging physicians now prefer secretagogues over rHGH specifically because pulsatile GH signaling is more natural and avoids some rHGH side effects.
Compare Somatropin (rHGH) side-by-sideResearch Use Only
This information is for educational research purposes only. This is not medical advice. Consult a qualified healthcare professional.