Somatropin (HGH): Recombinant Growth Hormone and Its Approvals
Recombinant human growth hormone — a 191-amino-acid polypeptide identical to the body's own pituitary GH, sold under brands including Humatrope and Genotropin.
What is Somatropin (HGH)?
Somatropin is recombinant human growth hormone, a 191-amino-acid single-chain polypeptide identical in sequence to the growth hormone naturally produced by the pituitary gland. It's FDA-approved under multiple brand names for specific indications — pediatric growth failure, adult growth hormone deficiency, and, for certain brands, conditions like HIV-associated wasting or short bowel syndrome. Dosing is highly individualized and titrated by a prescriber based on IGF-1 lab levels, not self-directed. Distribution or possession of somatropin for unapproved uses such as bodybuilding or anti-aging is a specific federal crime in the US, reflecting its history of non-medical misuse.
Quick facts
- Molecular Formula
- C990H1528N262O300S7
- Molecular Weight
- ~22,124 Da
- CAS Number
- 12629-01-5
- Half-Life
- ~20–30 minutes (serum)
- Class
- Recombinant human growth hormone (191-aa polypeptide)
- Brand Names
- Humatrope, Genotropin, Norditropin, Omnitrope, Saizen, Nutropin, Serostim, Zomacton
- Legal Status
- Prescription-only, FDA-approved for specific indications. Distribution/possession for unapproved use is a federal crime under 21 U.S.C. § 333(e)
- Category
- Growth Hormone
- Storage
- Store the lyophilized vial refrigerated (2-8°C) or at -20°C, away from light. Once reconstituted, keep refrigerated at 2-8°C and use promptly.
Dosing at a glance
Common clinical convention: a 5–10mg lyophilized vial reconstituted with 1–2mL bacteriostatic water, dosed daily via subcutaneous injection. Exact vial size and dilution vary by brand and pen device. Run the numbers in the reconstitution calculator.
Doses shown are those reported in published research, not a recommendation.
Somatropin (HGH) Mechanism of Action
Identical to Endogenous GH
Somatropin is manufactured via recombinant DNA technology to be structurally identical to the 191-amino-acid growth hormone naturally secreted by the pituitary gland. It binds GH receptors throughout the body, most importantly in the liver, stimulating production of IGF-1 — the hormone that mediates most of GH's downstream growth, tissue-repair, and metabolic effects.
Metabolic and Body Composition Effects
Beyond linear growth in children, somatropin promotes lipolysis (fat breakdown), supports lean-mass maintenance, and influences glucose metabolism — it has a mild insulin-antagonist effect at higher doses, which is part of why fasting glucose is monitored during therapy.
Somatropin (HGH) Dosage and Protocols
Individualized by Indication
Dosing varies substantially by brand, age, and indication. As examples: Genotropin/Omnitrope pediatric dosing typically starts up to 0.04–0.08 mg/kg/week divided into daily doses; adult GH-deficiency dosing typically starts much lower, around 0.1–0.2mg/day, and is titrated upward by a prescriber based on IGF-1 lab levels and tolerability. This is not a self-directed dose — it requires physician oversight and lab monitoring.
Somatropin (HGH) Side Effects and Safety
Common and Serious Risks
Common effects include injection-site reactions, fluid retention/edema, joint pain, and headache, especially early in therapy or at higher doses. More serious risks include worsened insulin resistance/elevated blood glucose, intracranial hypertension (rare), and theoretical concerns about tumor growth stimulation, which is why active malignancy is a contraindication. Diabetic retinopathy can worsen with GH therapy.
Somatropin (HGH) Research Evidence
Approved Indications
Somatropin brands are FDA-approved for a range of indications depending on the specific product: pediatric growth hormone deficiency and growth failure, adult growth hormone deficiency, Turner syndrome, and — for specific brands — HIV-associated wasting (Serostim) or short bowel syndrome (Zorbtive). Each brand has its own FDA-approved label and indication set; they are not interchangeable off-label without a prescriber's guidance.
Regulatory and Legal Status
Somatropin is prescription-only and FDA-approved for the specific indications listed on each brand's label. Distributing or possessing somatropin for unapproved uses — bodybuilding, anti-aging, athletic performance — is a federal crime in the US under 21 U.S.C. § 333(e), a statute specific to human growth hormone that goes beyond ordinary prescription-drug law, reflecting its history of non-medical misuse. It should only be obtained through a licensed prescriber for an approved indication.
Somatropin (HGH) Stacking and Combinations
Clinical Use Context
In its approved medical context, somatropin is prescribed as a standalone hormone-replacement therapy managed by an endocrinologist, with regular IGF-1 and glucose monitoring — not combined with other peptides in a stacking protocol.
Somatropin (HGH) Pharmacokinetics
Short Serum Half-Life, Longer Downstream Effect
Somatropin's serum half-life is short — roughly 20–30 minutes — but its biological effects last far longer because they're mediated through IGF-1, which has a much longer half-life and sustains the downstream metabolic and tissue effects well after the GH itself has cleared.
Contraindications
- active malignancy
- diabetic retinopathy
- acute critical illness
- closed epiphyses (pediatric growth-promotion context)
Frequently asked questions
What is a typical Somatropin (HGH) dose?
Published research protocols report Individualized by indication, daily, physician-titrated. This is the range described in the literature, not a recommendation.
What is the half-life of Somatropin (HGH)?
~20–30 minutes in serum (biological effects last much longer, mediated downstream through IGF-1).
Is Somatropin (HGH) backed by strong evidence?
Somatropin (HGH) carries a REGEN research grade of S. REGEN Research Tier S — official FDA approval, in continuous clinical use since 1985.
How is Somatropin (HGH) administered?
Routes reported in the literature: subcutaneous.
Who should avoid Somatropin (HGH)?
Contraindications noted in the literature include active malignancy, diabetic retinopathy, acute critical illness, closed epiphyses (pediatric growth-promotion context).