Lab-made human growth hormone. FDA-approved for growth failure and adult GH deficiency; distributing it for anti-aging is a federal crime.
Also called HGH, hGH, Human growth hormone, rhGH, Recombinant human growth hormone, Growth hormone, GH, Genotropin, Humatrope, Norditropin, Nutropin AQ, Omnitrope, Saizen, Serostim, Zomacton, Zorbtive, Accretropin, Skytrofa (lonapegsomatropin), Sogroya (somapacitan), Ngenla (somatrogon), Somatotropin
When Somatropin (human growth hormone)'s status or evidence changes, it's in the next morning's email.
Somatropin is recombinant human growth hormone: a 191-amino-acid protein identical to the hormone the pituitary makes. It raises IGF-1, which drives growth in children and, in adults, shifts the body toward more lean tissue and less fat. Many brands sell the same molecule as daily injections, including Genotropin, Humatrope, Norditropin, Omnitrope and Zomacton. Three weekly products work differently: Skytrofa (lonapegsomatropin, 2021) is somatropin on a carrier that releases it slowly, while Sogroya (somapacitan, 2020) and Ngenla (somatrogon, 2023) are modified growth hormones that stay in the blood longer.
Approved uses are specific: children with growth failure from growth hormone deficiency, Turner, Prader-Willi or Noonan syndrome, small size at birth, or idiopathic short stature, plus adults with proven growth hormone deficiency, and HIV wasting (Serostim). In adults with real deficiency, trials show more lean mass, less fat and a smaller waist. In healthy older people it is a different story. A review of 18 trials with 220 people on growth hormone found 2.1 kg more lean mass and 2.1 kg less fat, no change in weight or bone density, and more swelling, joint pain, carpal tunnel syndrome and diabetes.
US law treats growth hormone unlike most drugs. Under 21 U.S.C. 333(e), knowingly distributing it, or possessing it to distribute, for any use other than an FDA-approved one on a doctor's order is a felony punishable by up to 5 years in prison, or 10 if the offense involves someone under 18. That makes supplying it for anti-aging, bodybuilding or sports illegal, even with a prescription, because those uses are not FDA-authorized. Somatropin is also banned in sport at all times, and since March 2020 FDA regulates it as a biologic that compounding pharmacies cannot make.
What it binds to, and what happens inside the body after that, step by step.
Somatropin binds growth hormone receptors in the liver, fat, muscle and bone. The liver responds by making IGF-1, which carries most of the growth signal to growth plates. Growth hormone itself breaks down fat, builds protein and works against insulin, which is why it can raise blood sugar. It also makes the body hold sodium and water, the source of the swelling and joint pain that are its most common side effects.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
Decades of RCTs support somatropin for childhood growth disorders and adult growth hormone deficiency, where it improves body composition and, per the Endocrine Society, exercise capacity, bone and quality of life. In healthy older adults and athletes, systematic reviews find about 2 kg more lean mass and 2 kg less fat, but no clear gain in strength or endurance, and more side effects including diabetes. Weekly analogs matched or beat daily somatropin in phase 3 trials.
18 RCT populations, 220 healthy older adults given GH (mean age 69)
Lean mass +2.1 kg and fat -2.1 kg with no change in weight or bone density; more edema, joint pain, carpal tunnel, gynecomastia and diabetes.
Read the study27 study samples, 303 young fit adults given GH
Lean mass +2.1 kg, but strength and exercise capacity did not improve; more fluid retention and fatigue.
Read the study131 healthy adults aged 65 to 88, 26 weeks
GH raised lean mass (men +3.1 kg) but not strength; diabetes or glucose intolerance in 18 GH-treated men vs 7 without GH.
Read the study96 recreational athletes, 8 weeks
2 mg a day raised sprint capacity 3.9%; strength, power and endurance did not change, and the gain was gone 6 weeks after stopping.
Read the study301 treatment-naive adults with GH deficiency, 34 weeks plus extension
Truncal fat fell 1.53 percentage points more than placebo; results similar to daily GH through 86 weeks.
Read the study161 prepubertal children with GH deficiency, 52 weeks
Height velocity 11.2 cm a year on weekly lonapegsomatropin vs 10.3 cm a year on daily somatropin.
Read the study21 healthy men aged 61 to 81 with low IGF-1 (12 treated, 9 untreated), 6 months
Lean mass +8.8%, fat -14.4% and lumbar spine density +1.6% in the treated men; no change in untreated men.
Read the study6,284 recipients of cadaver-pituitary growth hormone (cohort)
7 confirmed CJD cases, all among those who began treatment before 1970; the reason pituitary GH was replaced by recombinant somatropin.
Read the studyNo preclinical studies are listed as key studies here. The human data above carries the evidence.
When a new Somatropin (human growth hormone) study in people is published, the daily email covers it.
These are questions the published research has not answered.
21 U.S.C. 333(e) makes it a crime to knowingly distribute, or possess with intent to distribute, human growth hormone for any use in humans other than treatment of a disease or recognized medical condition authorized by HHS under section 355 and ordered by a physician: up to 5 years in prison, or 10 years if the offense involves someone under 18. The statute defines human growth hormone as somatrem, somatropin or an analogue of either, and the DEA is authorized to investigate. This is stricter than the general rule that doctors may prescribe approved drugs off label. FDA's 2020 list of drugs deemed biologics also names Norditropin, Zomacton, Serostim (HIV wasting with cachexia), Nutropin, Nutropin AQ, Saizen, Zorbtive and Accretropin; not all of these are still marketed. The weekly products have different molecules (a PEG-linked prodrug, an albumin-binding analog and an hCG-CTP fusion protein) and different doses; they are not interchangeable mg for mg with daily somatropin. Prohibited at all times under WADA S2.2.3, which names growth hormone and the analogues lonapegsomatropin, somapacitan and somatrogon.
When the FDA or WADA changes Somatropin (human growth hormone)'s status, it's in the next morning's email.
How much of Somatropin (human growth hormone) is left after a single dose
Simple first-order model from the published half-life. Real clearance varies with dose, route, kidney and liver function and formulation. This is not a dosing schedule.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
In 220 healthy older adults across 18 trials, GH changed body composition by about 2 kg each way but did not change weight or bone density, and raised rates of swelling, joint pain, carpal tunnel and diabetes. The authors concluded it cannot be recommended as an anti-aging therapy.
A review of 303 young athletes found more lean mass but no gain in strength or exercise capacity. One 96-person trial found a 3.9% rise in sprint capacity that disappeared 6 weeks after stopping.
21 U.S.C. 333(e) makes distributing GH for any use other than an FDA-authorized one a felony. Ordinary off-label prescribing rules do not apply to growth hormone.
Skytrofa releases ordinary somatropin from a carrier. Sogroya and Ngenla are modified growth hormone molecules. All three have their own doses and are not swapped mg for mg.
Somatropin is a 22 kDa protein, and every FDA-approved somatropin product is an injection. We found no published trial showing that an oral or spray product sold as HGH raises growth hormone in the blood.
These pairings come up often. Almost none have been tested together in a trial, and the evidence note on each says so plainly.
Common among athletes and in anti-aging clinics to combine two body-composition signals.
EvidenceTested in two RCTs. In older men, the pair added 4.3 kg lean mass and marginal strength but caused carpal tunnel symptoms in 32%. In athletes, it raised sprint capacity 8.3%. Both are banned in sport, and GH distribution for this use is illegal in the US.
Discussed online to add the body's own GH pulses on top of injected GH.
EvidenceNever studied together. Stacking raises IGF-1 exposure with unknown safety.
Genotropin powder cartridges: refrigerate at 2 to 8 C until expiry, protect from light, do not freeze. Some single-dose devices may be kept up to 3 months at or below 25 C before mixing (label). Storage differs by brand.
Genotropin 5 mg and 12 mg cartridges: refrigerate at 2 to 8 C between uses and discard after 28 days; do not shake (label).
One email when a trial reads out, a label changes or the FDA acts on a peptide. Free, every source linked, unsubscribe any time.