Somatropin

What Somatropin does

Somatropin is lab-made human growth hormone. Its medical uses do not prove it slows aging or builds strength in healthy adults. Product-specific approvals cover growth hormone deficiency, certain childhood growth disorders, HIV wasting or short bowel syndrome. Swelling, joint pain and higher blood sugar are key risks.

• Different brands are approved for growth hormone deficiency in children and adults, several childhood growth disorders, HIV wasting and short bowel syndrome. (Drug label)
• In adults with growth hormone deficiency, trials found 3.1 kg less fat and 2.7 kg more lean mass on average. (Studied in a trial)
• In older adults, trials found 2.1 kg less fat and 2.1 kg more lean mass, with no clear change in weight. (Studied in a trial)
• People report better sleep, fullness, fat loss or recovery, though results and tolerance vary. (Reported by users)

Uses in the sources

• Approved for confirmed adult GH deficiency. A low IGF-1 level or age-related GH decline alone usually does not establish the diagnosis. (Drug label) (source)
• Product-specific approvals cover childhood GHD, Turner, Prader-Willi, Noonan, SHOX deficiency, SGA without catch-up growth and idiopathic short stature. (Drug label) (source)
• Serostim is approved for HIV wasting or cachexia. Zorbtive is approved for adults with short bowel syndrome receiving specialized nutrition support. (Drug label) (source)
• Used for anti-aging, but trials show small body-composition changes and more side effects. Longer life or preserved independence has not been shown. (Reported by users) (source)
• One short trial found a modest sprint gain. Strength, endurance and jump height did not improve significantly. (Studied in a trial) (source)
• Obesity trials found less fat and more lean mass, but no weight loss. Fasting blood sugar rose. (Studied in a trial) (source)
• A short human experiment increased tendon collagen synthesis. This does not prove that GH heals an injury. (Studied in a trial) (source)
• Studied as an IVF add-on. Cochrane found low to very low certainty evidence; it is not an FDA-approved fertility indication. (Studied in a trial) (source)

Somatropin dosage

Typical reported dose: Adult growth hormone deficiency: about 0.2 mg daily to start

• Adult GHD: low daily start: A starting dose of approximately 0.2 mg/day (range, 0.15–0.30 mg/day). once daily, under the skin. Drug label. Studied in: Adults with confirmed GH deficiency. (source)
• Adult GHD: Genotropin weight-based option: Start at not more than 0.04 mg/kg/week; increase to not more than 0.08 mg/kg/week at 4–8 week intervals. weekly total divided into daily injections, under the skin. Drug label. Studied in: Adults with confirmed GHD; weight dosing is less suitable in obesity. (source)
• Adult GHD: Humatrope or Zomacton weight dosing: Initiate at 0.006 mg/kg daily; increase as needed to a maximum of 0.0125 mg/kg daily. once daily, under the skin. Drug label. Studied in: Adults with confirmed GHD; not recommended for obese patients. (source)
• Adult GHD: historical Nutropin limits: Start at no more than 0.006 mg/kg/day; maximum 0.025 mg/kg/day at age ≤35, or 0.0125 mg/kg/day above 35. once daily, under the skin. Drug label. Studied in: Adults with GHD; Nutropin AQ NuSpin supply was discontinued. (source)
• HIV wasting: daily Serostim: 0.1 mg/kg once daily, up to 6 mg: <35 kg, 0.1 mg/kg; 35–45 kg, 4 mg; 45–55 kg, 5 mg; >55 kg, 6 mg. once daily at bedtime, under the skin. Drug label. Studied in: Adults with HIV-associated wasting or cachexia. (source)
• HIV wasting: alternate-day Serostim: A starting dose of 0.1 mg/kg every other day should be considered in patients at increased risk for adverse effects. every other day, under the skin. Drug label. Studied in: Adults with HIV wasting at higher risk of GH side effects, such as glucose intolerance. (source)

These are doses reported in labels, trials or user reports, not a personal plan. Check the source behind each one.

Work out syringe units with the dosing calculator

How to mix Somatropin

Comes as: Lyophilized powder in product-specific vials or two-chamber cartridges, Ready-to-use solution in cartridges or prefilled pens, Single-dose and single-patient-use presentations.

Mixed with: Use the exact product’s supplied or specified diluent. Preservative content and allowed storage differ; bacteriostatic water is not universal..

Common vial sizes: 4, 5, 5.8, 6, 8.8, 10 mg. Common water amounts: mL.

• Genotropin 5/12 mg two-chamber cartridges use their built-in diluent; final concentrations are 5/12 mg per mL.
• Genotropin MiniQuick delivers 0.25 mL once. After mixing, it may be refrigerated for up to 24 hours before use.
• Zorbtive 8.8 mg: add 1 mL if weight >44 kg, or 2 mL if ≤44 kg, using the label’s specified diluent.
• Zomacton 5 mg: up to 14 days refrigerated with its supplied diluent; 10 mg: up to 28 days with its supplied diluent.
• Gently swirl as directed; do not shake. Do not use cloudy solution or visible particles.
• Community mixing volumes are recorded separately. Label storage times do not validate the shelf life of unknown online vials.
• GH IU measure potency; U-100 syringe marks measure volume. The conversion depends on the exact concentration.
• Omnitrope 5.8 mg vial: the specified 1.14 mL diluent yields a labeled final concentration of 5 mg/mL. Vial mass divided by added diluent is not the label concentration.

Before mixing: Genotropin and Omnitrope: 2–8°C, protected from light; do not freeze. Serostim powder kits: 15–30°C. Check the exact product.

After mixing: Genotropin cartridges: 28 days at 2–8°C. Omnitrope vial: 21 days. Serostim 4 mg with its bacteriostatic diluent: 14 days; 5/6 mg with sterile water: use immediately.

Somatropin side effects and risks

Reported side effects

• Swelling and fluid buildup: Adult GHD trials: peripheral swelling 17.5% GH vs 5.1% placebo at 6 months., moderate. Report new swelling; dose reduction often helps. New breathlessness needs urgent assessment. (source)
• Joint pain: Adult GHD: 17.3% GH vs 4.2% placebo. HIV wasting daily dose: 36.4% vs 11.3%., moderate. Report persistent pain and review the dose. (source)
• Hand tingling or numbness: Adult GHD: tingling 9.6% GH vs 1.9% placebo; carpal tunnel 2% in a 3031 person extension., moderate. Review dose and nerve symptoms promptly; weakness or persistent numbness needs assessment. (source)
• Headache: Adult GHD: 9.9% GH vs 7.7% placebo., mild. A severe headache with vomiting or vision changes needs urgent care. (source)
• Muscle pain: Adult GHD: 4.9% GH vs 1.6% placebo; HIV wasting daily dose: 30.4% vs 11.7%., moderate (source)
• High blood sugar or new diabetes: Adult extension: diabetes 12/3031, 0.4%; all had risk factors. Rates depend strongly on dose and population., serious. Check glucose and HbA1c; diabetes medicines may need adjustment. (source)
• Injection-site pain and local fat loss: Short bowel trial: injection site pain 31% GH alone vs 0% control. GHD injection site rates were not quantified., moderate. Rotate sites and review persistent redness, lumps or skin changes. (source)
• Fluid retention at short-bowel doses: Peripheral edema: 69% GH, 81% GH plus glutamine, 11% control; 16, 16 and 9 participants., moderate (source)
• Raised pressure around the brain: Reported with GH, usually within the first 8 weeks; an incidence rate is unavailable., serious. Stop and seek urgent assessment for headache with vomiting or vision change. (source)
• Severe allergic reaction: Anaphylaxis and angioedema have been reported after marketing; frequency cannot be estimated., serious. Stop and get emergency care for throat swelling, wheezing or trouble breathing. (source)
• Pancreatitis: Reported in children and adults; a reliable frequency is unavailable., serious. Get urgent care for severe ongoing upper belly pain or repeated vomiting. (source)
• Unmasked thyroid or adrenal deficiency: unknown, serious. Review free T4 and adrenal function, especially with known pituitary disease. (source)
• Hip growth-plate slip in children: unknown, serious. A new limp or hip or knee pain needs prompt assessment. (source)
• Second tumors in childhood cancer survivors: Risk is most relevant after prior head radiation. Active cancer is contraindicated., serious (source)

Stop and get help if

• Severe headache with vomiting, blurred vision or double vision: Stop GH and get urgent assessment for raised pressure around the brain.
• Throat or face swelling, wheezing or trouble breathing: Stop GH and get emergency care.
• Chest pain, fainting, sudden breathlessness or rapidly worsening swelling: Get emergency care.
• Severe ongoing upper belly pain, especially with repeated vomiting: Stop GH and seek urgent assessment for pancreatitis.
• Marked thirst or urination with vomiting, deep breathing or confusion: Get urgent care and check glucose; severe high blood sugar can be dangerous.
• Sweating, shaking, confusion or collapse while also using insulin: Check glucose promptly. Persistent symptoms, inability to swallow or unconsciousness need emergency care.
• Severe weakness, vomiting or fainting in someone with pituitary disease: Get urgent assessment for adrenal crisis and follow the prescribed adrenal emergency plan.
• A new limp, hip pain or knee pain in a child receiving GH: Seek prompt assessment for a slipped growth plate.

Who should avoid it

• activeCancer: Active cancer is a label contraindication. Any prior tumor must be inactive and its treatment completed before GH is considered.
• other: High-dose GH increased deaths after major surgery, trauma or acute respiratory failure. Acute critical illness is a label contraindication.
• diabeticRetinopathy: Active proliferative or severe nonproliferative diabetic retinopathy is contraindicated. Other retinopathy still needs clinician review.
• other: Known serious allergy to somatropin or this product’s ingredients is contraindicated.
• other: The Genotropin label contraindicates use for growth promotion in children with closed epiphyses (growth plates). This does not prohibit indicated growth-hormone replacement in adults with confirmed GH deficiency.
• pregnant: Human pregnancy data are insufficient to determine developmental risk.
• breastfeeding: The label reports limited milk data and no reported infant harm; safety evidence remains limited.
• tryingToConceive: Fertility add-on studies do not establish fetal safety or a washout interval.
• under18: Pediatric GH has specific approved growth-disorder uses that require specialist dosing and follow-up.
• cancerHistory: Prior cancer, head radiation or a pituitary tumor needs recurrence surveillance. Childhood cancer survivors can develop second tumors.
• diabetes: GH can reduce insulin sensitivity. Diabetes medicines may need adjustment; glucose should be monitored.
• surgeryPlanned: Discuss planned surgery. Safety of continuing replacement GH during acute critical illness has not been established.
• heartCondition: Fluid retention may matter more with heart disease. Review swelling, weight gain and breathlessness.
• uncontrolledBloodPressure: Fluid retention and rapid weight gain need review before GH exposure or dose escalation.
• kidneyDisease: Adult renal-impairment pharmacology data are limited. Childhood kidney-growth indications do not establish an adult dosing rule.
• liverDisease: Adult liver-impairment pharmacology studies are lacking for Genotropin; no standard dose adjustment is established.
• pancreatitisHistory: Pancreatitis has been reported. Review prior episodes and seek prompt care for new severe belly pain.
• sleepApnea: Review snoring or breathing pauses. In Prader-Willi syndrome, severe obesity or major breathing impairment can preclude GH.
• other: Severe obesity, prior upper-airway obstruction or sleep apnea, or severe breathing impairment in pediatric Prader-Willi syndrome is contraindicated.
• other: GH may uncover low cortisol or low thyroid hormone in people with pituitary disease. Replacement doses may need adjustment.
• testedAthlete: WADA prohibits GH at all times under S2.2.3, including use outside competition.

Interactions

• Insulin and other glucose-lowering drugs: GH can raise blood sugar and change drug needs. Insulin or sulfonylureas can cause low sugar if dose needs fall after GH is reduced or stopped.
• Glucocorticoids: GH may lower available cortisol and uncover adrenal insufficiency. Steroid replacement may need adjustment; excess steroids can blunt GH effects.
• Oral estrogen: Oral estrogen can lower the IGF-1 response and increase GH dose needs. Starting, stopping or changing estrogen route can alter the required dose.
• Thyroid hormone: GH may uncover central hypothyroidism. Free T4 and replacement dose may need review; extra thyroid hormone is not a routine GH add-on.
• CYP-metabolized medicines: Somatropin may alter clearance of CYP-metabolized drugs. The label advises monitoring; the size and direction of each interaction are uncertain.
• Other GH products or secretagogues: Duplicate GH exposure or adding release-stimulating drugs has no established healthy-adult benefit. Shared GH/IGF-1 effects may add risk.
• IGF-1 drugs: The cited bodybuilding regimens have no controlled safety evidence. Adding another growth signal does not establish greater benefit or safer glucose control.

Product quality risks

• FDA reports counterfeit and unapproved HGH entering the supply chain; an online vial or pen may not be a licensed product.
• A 2009 mass-spectrometry study found distinct oxidation, deamidation and chain-cleavage patterns in counterfeit and reference GH products.
• A 2025 analytical study detected GH in all 34 suspect products tested. Detection did not prove correct dose, sterility or clinical safety.
• Product identity and purity tests do not by themselves establish potency, freedom from endotoxin or sterility.
• An unknown vial’s storage history and mixing stability are unverified. Clear appearance cannot authenticate its contents.

What to expect

At least 126 trials or study populations appear in seven key reviews. This minimum is not a complete count of separate human studies.

Key studies

• Adult GHD: six approval trials: Lean mass and total body water rose; fat mass and waist fell versus placebo. The label does not give numeric changes. (source)
• Adult GHD: early replacement trial: GH: lean mass +5.5 ±1.1 kg and fat mass -5.7 ±0.9 kg, mean ±SE. Neither changed significantly with placebo. (source)
• Adult GHD: four approval trials: Lean mass +2.59 vs -0.22 kg; body fat -3.27 vs +0.56 kg, GH vs placebo. (source)
• Adult GHD: older weight-based dosing: Fat fell and lean mass rose with GH. Strength, endurance, quality of life and bone density did not differ significantly. (source)
• Adult GHD: low start versus weight dosing: Mean ±SD: 0.70 ±0.32 mg/day weight-based vs 0.54 ±0.22 mg/day individualized; P<0.001. (source)
• Adult GHD: 37 randomized trials: GH vs placebo: fat -3.1 kg and lean mass +2.7 kg, weighted differences. (source)

Somatropin FAQ

• Is Somatropin FDA-approved? Yes: Genotropin (adult/pediatric GHD; pediatric Prader-Willi, Turner, SGA without catch-up growth and idiopathic short stature.); Humatrope (adult/pediatric GHD; pediatric Turner, SHOX deficiency, SGA and idiopathic short stature.); Norditropin (adult/pediatric GHD; pediatric Noonan, Turner, SGA, Prader-Willi and idiopathic short stature.). FDA restricts distribution for unapproved uses, including anti-aging, bodybuilding and athletic enhancement, under 21 USC 333(e). “Research use only” does not authorize human use.
• How do people take it? Under the skin, once daily. Source: drug label.
• What's the difference between Somatropin and Retatrutide? Somatropin: prescription human growth hormone, with no proven anti-aging benefit. Retatrutide: an experimental weekly injection with phase 3 weight-loss results. Why people pair them: users combine them for fat loss or to offset GH-related glucose effects. No controlled trial was found for this stack.
• Can I take it with Retatrutide? Users combine them for fat loss or to offset GH-related glucose effects. No controlled trial was found for this stack. Claims of glucose protection are unproven; each drug’s risks remain. Source: reported by users. Ask a doctor before combining anything.
• Is it banned in sport? Yes. It is banned in and out of competition (WADA 2026). Prohibited in and out of competition under the 2026 list.
• How long does a mixed vial last? Genotropin cartridges: 28 days at 2–8°C. Omnitrope vial: 21 days. Serostim 4 mg with its bacteriostatic diluent: 14 days; 5/6 mg with sterile water: use immediately.