Somatropin: uses, dosing, side effects & brands
Somatropin is a recombinant human growth hormone sold in the U.S. under 16 brand and generic names, for cachexia, dwarfism and heart failure. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Recombinant Human Growth Hormone
- Treats (across its forms)
- Cachexia, Dwarfism and Heart Failure
- Available as
- Kit · Injectable
- Sold as
- 16 products — Bio-Tropin, Zomacton and Norditropin, and others
- Prescription?
- Prescription only
- Generic available?
- Not in our catalog
- Half-life
- about 3 hours (after subcutaneous injection)
How Bio-Tropin is dosed
From the FDA label for Bio-Tropin (application BLA019774). Other somatropin products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Administer by subcutaneous injection to the back of upper arm, abdomen, buttock, or thigh with regular rotation of injection sites ( 2.1 ) Pediatric dosage: Divide the calculated weekly dosage into equal doses given either 3, 6, or 7 days per week ( 2.2 ) GH deficiency : 0.18 mg/kg/week to 0.3 mg/kg/week ( 2.2 ) Turner syndrome: Up to 0.375 mg/kg/week ( 2.2 ) ISS : Up to 0.37 mg/kg/week ( 2.2 ) SHOX deficiency: 0.35 mg/kg/week ( 2.2 ) SGA: Up to 0.47 mg/kg/week ( 2.2 ) Adult dosage: Either of the following two dosing regimens may be used: Non-weight based dosing : Initiate with a dose of approximately 0.2 mg/day (range, 0.15 mg/day to 0.3 mg/day) and increase the dose every 1 to 2 months by increments of approximately 0.1 mg/day to 0.2 mg/day, according to individual patient requirements ( 2.3 ) Weight-based dosing (Not recommended for obese patients) : Initiate at 0.006 mg/kg daily and increase the dose according to individual patient requirements to a maximum of 0.0125 mg/kg daily ( 2.3 ) See Full Prescribing Information for reconstitution instructions ( 2.4 ) 2.1 Administration and Use Instructions Therapy with ZOMACTON should be supervised by a physician who is experienced in the diagnosis and management of patients with the conditions for which ZOMACTON is indicated [see Indications and Usage (1) ]. Fundoscopic examination should be performed routinely before initiating…
Everything below is the FDA label for Bio-Tropin (kit). Somatropin is also sold as injectable, and those are different medicines to take — follow the label for the one you were prescribed.
Bio-Tropin side effects
The following important adverse reactions are also described elsewhere in the labeling: Increased mortality in patients with acute critical illness [see Warnings and Precautions (5.1) ] Fatalities in pediatric patients with Prader-Willi syndrome [see Warnings and Precautions (5.2) ] Neoplasms [see Warnings and Precautions (5.3) ] Glucose intolerance and diabetes mellitus [see Warnings and Precautions (5.4) ] Intracranial hypertension [see Warnings and Precautions (5.5) ] Severe hypersensitivity [see Warnings and Precautions (5.6) ] Fluid retention [see Warnings and Precautions (5.7) ] Hypoadrenalism [see Warnings and Precautions (5.8) ] Hypothyroidism [see Warnings and Precautions (5.9) ] Slipped capital femoral epiphysis in pediatric patients [see Warnings and Precautions (5.10) ] Progression of preexisting scoliosis in pediatric patients [see Warnings and Precautions (5.11) ] Pancreatitis [see Warnings and Precautions (5.12) ] Risk of Serious Adverse Reactions in Infants due to Benzyl Alcohol Preservative [see Warnings and Precautions (5.13) ] Lipoatrophy [see Warnings and Precautions (5.14) ] Common adverse reactions reported in adult and pediatric patients include: upper respiratory infection, fever, pharyngitis, headache, otitis media, edema, arthralgia, paresthesia, myalgia, carpal tunnel syndrome, peripheral edema, flu syndrome, hypothyroidism, hyperglycemia, and…
Who shouldn’t take Bio-Tropin
ZOMACTON is contraindicated in patients with: Acute critical illness after open heart surgery, abdominal surgery or multiple accidental trauma, or those with acute respiratory failure due to the risk of increased mortality with use of pharmacologic doses of somatropin [see Warnings and Precautions (5.1) ] . Pediatric patients with Prader-Willi syndrome who are severely obese, have a history of upper airway obstruction or sleep apnea, or have severe respiratory impairment due to the risk of sudden death [see Warnings and Precautions (5.2) ] . Active malignancy [see Warnings and Precautions (5.3) ] . Known hypersensitivity to somatropin or to any excipients of ZOMACTON. Systemic hypersensitivity reactions, including anaphylaxis and angioedema, have been reported with postmarketing use of somatropins [see Dosage and Administrations (2.4) , Warnings and Precautions (5.6) ] . Active proliferative or severe non-proliferative diabetic retinopathy. Pediatric patients with closed epiphyses. Acute critical illness ( 4 , 5.1 ) Pediatric patients with Prader-Willi syndrome who are severely obese, have a history of upper airway obstruction or sleep apnea, or have severe respiratory impairment due to risk of sudden death ( 4 , 5.2 ) Active malignancy ( 4 ) Hypersensitivity to ZOMACTON, its excipients, or diluents ( 4 ) Active proliferative or severe non-proliferative diabetic retinopathy ( 4 ) Pediatric patients with closed epiphyses ( 4 )
Bio-Tropin drug interactions
Table 7 includes a list of drugs with clinically important drug interactions when administered concomitantly with ZOMACTON and instructions for preventing or managing them. Table 7: Clinically Important Drug Interactions with ZOMACTON Glucocorticoids Clinical Impact: Microsomal enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD-1) is required for conversion of cortisone to its active metabolite, cortisol, in hepatic and adipose tissue. ZOMACTON inhibits 11βHSD-1. Consequently, individuals with untreated GH deficiency have relative increases in 11βHSD-1 and serum cortisol. Initiation of ZOMACTON may result in inhibition of 11βHSD-1 and reduced serum cortisol concentrations. Intervention: Patients treated with glucocorticoid replacement for hypoadrenalism may require an increase in their maintenance or stress doses following initiation of ZOMACTON [seeWarnings and Precautions (5.8)]. Examples: Cortisone acetate and prednisone may be affected more than others since conversion of these drugs to their biologically active metabolites is dependent on the activity of 11βHSD-1. Pharmacologic Glucocorticoid Therapy and Supraphysiologic Glucocorticoid Treatment Clinical Impact: Pharmacologic glucocorticoid therapy and supraphysiologic glucocorticoid treatment may attenuate the growth promoting effects of ZOMACTON in pediatric patients. Intervention: Carefully adjust glucocorticoid replacement dosing in pediatric patients receiving glucocorticoid treatments to avoid both hypoadrenalism and an inhibitory effect on growth. Cytochrome P450-Metabolized Drugs Clinical Impact: Limited published data indicate that somatropin treatment increases cytochrome P450 (CP450)-mediated antipyrine clearance. ZOMACTON may alter the clearance of compounds known to be metabolized by CP450 liver enzymes. Intervention: Careful monitoring is advisable when ZOMACTON is administered in combination with drugs metabolized by CP450 liver enzymes. Oral Estrogen Clinical Impact: Oral estrogens may reduce the serum IGF-1 response to ZOMACTON. Intervention: Patients receiving oral estrogen replacement may require greater ZOMACTON dosages [seeDosage and Administration (2.2)] . Insulin and/or Other Hypoglycemic Agents Clinical Impact: Treatment with ZOMACTON may decrease insulin sensitivity, particularly at higher doses. Intervention: Patients with diabetes mellitus may require adjustment of their doses of insulin and/or other hypoglycemic agents [seeWarnings and Precautions (5.4)]. Glucocorticoids: Patients treated with glucocorticoid for hypoadrenalism may require an increase in their maintenance or stress doses following initiation of ZOMACTON ( 7 ) Pharmacologic Glucocorticoid Therapy and Supraphysiologic Glucocorticoid Treatment: Adjust glucocorticoid replacement dosing in pediatric patients receiving glucocorticoid treatment to avoid both hypoadrenalism and an inhibitory effect on growth. ( 7 ) Cytochrome P450-Metabolized Drugs: ZOMACTON may alter the clearance. Monitor carefully if used with ZOMACTON ( 7 ) Oral Estrogen: Larger doses of ZOMACTON may be required ( 7 ) Insulin and/or Other Hypoglycemic Agents: Dose adjustment of insulin or hypoglycemic agent may be required ( 5.4 , 7 )
Every somatropin product we track (16)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 72/100 | Prescription | Kit | No data | — | View → | |
| 2 | 72/100 | Prescription | Kit | No data | — | View → | |
| 3 | 70/100 | Prescription | Injectable | No data | — | View → | |
| 4 | 70/100 | Prescription | Injectable | No data | — | View → | |
| 5 | 70/100 | Prescription | Injectable | No data | — | View → | |
| 6 | 70/100 | Prescription | Injectable | No data | — | View → | |
| 7 | 70/100 | Prescription | Injectable | No data | — | View → | |
| 8 | 70/100 | Prescription | Injectable | No data | — | View → | |
| 9 | 70/100 | Prescription | Injectable | No data | — | View → | |
| 10 | 70/100 | Prescription | Injectable | No data | — | View → |
How long somatropin keeps
The date on a sealed pack is not the only one: some somatropin labels start a second clock once the product is opened or mixed, as short as 21 days.
Does somatropin expire? The in-use limits and storage rules from its labelsSomatropin and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for somatropin: levels in milk, effects in breastfed infants, and the drugs it would consider insteadLimited data indicate that exogenous somatropin does not increase normal breastmilk concentrations of growth hormone and that no adverse effects are experienced by the breastfed infants of mothers who receive somatropin. Growth hormone plasma concentration naturally increase in the first 3 days postpartum, which is thought to help increase milk production. Small studies by one group of investigators found that milk output increases from 19% to 36% after a 7-day course of somatropin. Because mothers were not given extensive breastfeeding support in these studies, the usefulness of the drug as a galactogogue in mothers given adequate breastfeeding support is not known. Galactogogues should never replace evaluation and counseling on modifiable factors that affect milk production.
National Institute of Child Health and Human Development, record revised September 15, 2024. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about somatropin
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 6,551 reports naming somatropin, and the FDA flagged 75% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- device leakage291 reports
- headache289 reports
- injection site pain235 reports
- drug dose omission by device211 reports
- fatigue185 reports
- pyrexia142 reports
- sleep apnoea syndrome142 reports
- arthralgia134 reports
Read these as a signal, not a rate. A report does not mean somatropin caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 26, 2026.
How long somatropin stays in your system
The elimination half-life of somatropin is about 3 hours (after subcutaneous injection). Somatropin is recombinant human growth hormone, given by subcutaneous injection. Its true elimination half-life is very short — the label reports a mean terminal half-life of only 0.4 hours (about 24 minutes) after intravenous dosing. After the usual subcutaneous injection the apparent half-life is longer, about 3.0 hours in growth-hormone-deficient adults, because slow absorption from the injection site (not elimination) becomes rate-limiting. So the drug itself clears quickly, but a subcutaneous dose is released over several hours. This half-life is not a drug-test detection window: growth hormone use is detected by anti-doping tests through downstream biomarkers (e.g., IGF-1) and isoform ratios that stay altered for days, far longer than the hormone's own half-life. Genotropin was not studied in patients with renal or hepatic impairment.
GENOTROPIN (somatropin) FDA label — DailyMed ↗Half-life is how long the body takes to clear half a dose. It is not the same as how long a drug test can detect it, and it varies with age, kidney and liver function.
Related calculators
Frequently asked questions
What is Bio-Tropin?
Bio-Tropin (Somatropin) is a recombinant human growth hormone used to treat Cachexia, Dwarfism, Heart Failure, Noonan Syndrome.
What kind of drug is somatropin?
The FDA classifies somatropin as a recombinant human growth hormone. Recombinant human growth hormone is a lab-made copy of the body's own growth hormone. It signals the liver and other tissues to make insulin-like growth factor-1 (IGF-1), which drives cells to take up protein and divide, promoting bone, muscle, and tissue growth. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
How long does somatropin stay in your system?
The elimination half-life of somatropin is about 3 hours (after subcutaneous injection) — that is how long the body takes to clear half of a dose. Somatropin is recombinant human growth hormone, given by subcutaneous injection. Its true elimination half-life is very short — the label reports a mean terminal half-life of only 0.4 hours (about 24 minutes) after intravenous dosing. After the usual subcutaneous injection the apparent half-life is longer, about 3.0 hours in growth-hormone-deficient adults, because slow absorption from the injection site (not elimination) becomes rate-limiting. So the drug itself clears quickly, but a subcutaneous dose is released over several hours. This half-life is not a drug-test detection window: growth hormone use is detected by anti-doping tests through downstream biomarkers (e.g., IGF-1) and isoform ratios that stay altered for days, far longer than the hormone's own half-life. Genotropin was not studied in patients with renal or hepatic impairment. Half-life is not the same as how long a drug test can detect the drug, and it varies with age, kidney and liver function.
Can you take somatropin with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run somatropin against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is somatropin sold under?
We track 16 somatropin-containing products in the U.S.: Bio-Tropin, Zomacton, Norditropin, Norditropin Flexpro, Norditropin Nordiflex, Nutropin, Nutropin Aq and Nutropin Aq Nuspin, and 8 more. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does somatropin come in?
Across the brands we track, somatropin is currently marketed as kit and injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic somatropin?
We do not currently list a generic-labelled somatropin product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.
Cite this page
- APA
- pharmaranks. (2026, July 24). Somatropin: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/somatropin
- MLA
- “Somatropin: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/somatropin.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for somatropin on DailyMed (NIH) ↗.