HGH (Somatropin)

Overview

HGH, or somatropin, is a recombinant version of human growth hormone that is identical to the 191-amino-acid hormone the pituitary gland produces naturally. It is manufactured as an injectable prescription medicine and stimulates the liver and other tissues to release insulin-like growth factor 1 (IGF-1), which drives most of its effects on muscle, fat, and connective tissue. In medicine it is used to correct a measured deficiency; in the fitness and anti-aging world it is used to try to restore more youthful hormone levels.

Evidence Quality

The evidence base is split. For diagnosed growth hormone deficiency in children and adults, somatropin is well studied and FDA-approved, with clear benefits on growth, body composition, and quality of life. For healthy adults using it to slow aging or build muscle, the evidence is much weaker: controlled trials show only modest changes alongside a high rate of side effects, which is why this use remains unapproved.

What the Research Shows

The classic 1990 study by Rudman and colleagues found that older men given growth hormone gained lean body mass, lost fat, and increased skin thickness over six months. Later reviews, including a 2007 systematic review of growth hormone in the healthy elderly, confirmed small improvements in body composition but also documented frequent edema, joint pain, carpal tunnel syndrome, and impaired glucose tolerance. The consensus is that the changes are real but modest, and that they come with meaningful metabolic trade-offs.

Dosage Notes

Clinical dosing for deficiency is low, usually around 0.2 to 0.4 mg per day, titrated by a physician against IGF-1 levels. Non-medical protocols are described in International Units: roughly 1 to 2 IU per day for anti-aging or hormone optimization, and 2 to 4 IU per day for body composition or muscle, sometimes split between a morning and a pre-bed injection. Because 1 IU is about 0.33 mg, these recreational doses often run higher than true replacement doses. The standard advice is to start at 1 IU and escalate slowly to limit water retention and joint pain.

Who Should Be Cautious

Growth hormone lowers insulin sensitivity and can raise blood sugar, so anyone who is prediabetic, diabetic, or metabolically at risk should be especially careful and monitor glucose closely. It is contraindicated in people with active cancer, acute critical illness, or certain forms of diabetic eye disease, because it can promote cell growth. Chronic high doses can produce acromegaly-like changes, such as enlargement of the hands, feet, jaw, and internal organs.

Availability

Somatropin is a legitimate FDA-approved drug sold under brand names such as Norditropin, Genotropin, Humatrope, and Omnitrope, and it legally requires a prescription. Product sold by research or peptide vendors is labeled not for human consumption and is not approved for the anti-aging, athletic, or bodybuilding uses it is marketed toward. It is also on the World Anti-Doping Agency prohibited list.

Bottom Line

For a diagnosed deficiency, growth hormone is an effective, well-established therapy. For healthy adults chasing anti-aging or physique benefits, the gains are modest and the risks, particularly to blood sugar and joints, are real and dose-dependent. Anyone considering it should do so under medical supervision with regular monitoring of IGF-1, glucose, and blood pressure.