Class comparison

HGH vs peptides: what the two actually are

By the Decadewise team Education only Last reviewed 27 July 2026 Source reporting only

Short answer

The definition: HGH is growth hormone itself, and the recombinant version, somatropin, is a chain of 191 amino acids weighing about 22,124 daltons with a sequence identical to the pituitary hormone.

Why the comparison is loose: somatropin is a peptide chain too, just a long one. The everyday split sets it against much shorter sequences, though those do not share one mechanism: the releasing factors act one step upstream of the pituitary, while the metabolic and somatostatin peptides in the table below act on entirely different receptors.

Where each acts: somatropin supplies the hormone directly. A releasing-factor analog such as tesamorelin, 44 amino acids plus a hexenoyl group, works on the pituitary instead of replacing its output.

What is approved: somatropin carries FDA-approved indications across pediatric growth failure and adult deficiency. Tesamorelin carries one, for excess abdominal fat in HIV lipodystrophy.

The legal line: a federal statute, 21 U.S.C. 333(e), names growth hormone specifically, defining it as somatrem, somatropin, or an analogue of either. How far "analogue" reaches is not settled by that text.

On this page

Short answer The molecules, by size Where each one acts What is approved, and for what The statute that treats hGH apart Is HGH a peptide? What is a secretagogue? Any approved GH peptides? How does anti-doping split them? Does the statute cover peptides? More from the library Sources The disclaimer

The molecules, laid out by size

Where the intuition breaks: people file HGH under hormones and everything else under peptides, but every molecule in the table below is an amino acid chain. What separates them on this table is length. The labels also describe different manufacturing routes and different receptors, though neither follows from length alone.

Chain length and molecular weight, as each label states them

Molecule	Chain	Molecular weight
Somatropin (Genotropin)	191 amino acid residues	22,124 daltons
Somatropin (Norditropin)	191 amino acids	about 22,000 daltons
Tesamorelin (Egrifta SV)	44 amino acids plus a hexenoyl moiety	5135.9 Da
Tirzepatide (Mounjaro)	GIP-based sequence, modified	4813.53 Da
Semaglutide (Ozempic)	GLP-1 analog, modified	4113.58 g/mol
Octreotide (Sandostatin)	cyclic octapeptide	1019.3 g/mol

Somatropin is roughly four times the mass of the next chain down.

How each one is made: both somatropin labels describe production by recombinant DNA technology in Escherichia coli. The Ozempic label describes the semaglutide backbone as produced by yeast fermentation, and the Egrifta SV label describes tesamorelin as synthetic.

What the labels state about it: the somatropin labels name recombinant production in E. coli, the Ozempic label names yeast fermentation, and the Egrifta SV label calls tesamorelin synthetic. Those are the routes each document reports for its own product. None of them states a general rule tying chain length to manufacturing method, and we do not supply one.

Where each one acts in the axis

Somatropin, the hormone itself: the labels describe a protein whose amino acid sequence is identical to pituitary growth hormone. Replacing endogenous output is how the adult deficiency indication reads; the pediatric indications on the same labels are not all replacement of endogenous output. Norditropin reports that a single 4mg dose in healthy adults with suppressed endogenous hormone raised mean IGF-1 from 190 ng/mL before the dose to a peak of 276 ng/mL at about 24 hours.

Tesamorelin, the upstream analog: the label describes a growth hormone-releasing factor analog, which acts on the pituitary rather than at the hormone's own receptor. The pivotal trial reported IGF-1 rising 81.0% in the tesamorelin group against a 5.0% fall on placebo over 26 weeks.

What the half-lives show about the difference: the tesamorelin label prints two figures from two formulations. Mean elimination half-life is 8 minutes after a single 1.4mg dose of Egrifta SV, the 2mg per vial formulation, in healthy subjects. Absolute bioavailability is less than 4% after a 2mg dose of the original Egrifta, the 1mg per vial formulation, in healthy adults. Somatropin's subcutaneous half-life is reported at 3.0 hours for Genotropin and 7 to 10 hours for Norditropin.

The third class: anti-doping documentation lists growth hormone secretagogues and their mimetics as a separate group from releasing hormones, with ibutamoren and ipamorelin among the examples. One name in that group does hold a US approval: macimorelin, marketed as Macrilen, approved in 2017 as a diagnostic for adult growth hormone deficiency.

What is approved, and for what

The somatropin file is broad: Genotropin lists indications covering pediatric growth failure from inadequate endogenous secretion, Prader-Willi syndrome, small for gestational age without catch-up growth by age two, Turner syndrome, idiopathic short stature, and adult growth hormone deficiency.

And it is bounded: the Norditropin label states plainly that it is not indicated for the treatment of non-growth-hormone-deficient adults, and reports two placebo-controlled trials in critically ill non-deficient adults where mortality ran 42% against 19% on placebo.

The tesamorelin file is narrow: one indication, the reduction of excess abdominal fat in HIV-infected adults with lipodystrophy, with the label stating in its own highlights that it is not indicated for weight loss management.

What that asymmetry means: the approved uses cluster around deficiency and a specific disease state. Neither document contains an indication for performance, body composition in healthy adults, or aging.

The statute that treats growth hormone on its own

The provision: 21 U.S.C. 333(e) makes it an offense to knowingly distribute, or possess with intent to distribute, human growth hormone for any use in humans other than the treatment of a disease or other recognized medical condition, where that use has been authorized by the Secretary and is pursuant to a physician's order.

The penalty structure: the statute sets up to 5 years in prison, rising to 10 years where the offense involves an individual under 18, and directs that a conviction be treated as a felony violation of the Controlled Substances Act for forfeiture purposes.

How narrowly it is defined: paragraph (4) defines human growth hormone for that subsection as somatrem, somatropin, or an analogue of either. That definition is the reason the provision does not read across to every peptide.

What we are not doing here: giving legal advice or reading the phrase "an analogue of either" for any particular compound. That is a question for a lawyer looking at facts, not a reference page.

Is HGH a peptide?

Chemically it belongs to the same family, and both somatropin labels describe it as a protein of 191 amino acid residues with a sequence identical to pituitary growth hormone. The word people usually reach for is protein, because the chain is long enough that the two terms blur.

Where the distinction on this page sits: not chemistry but position in the axis. Somatropin is the hormone. The releasing factors and secretagogues set against it here act on the gland that makes the hormone rather than supplying it.

Why the label of the category matters: the statute above is written around somatrem, somatropin and their analogs, so a naming argument turns into a legal one faster here than in most compound comparisons.

What is a growth hormone secretagogue?

A compound that prompts the pituitary to release growth hormone rather than supplying the hormone itself. Anti-doping documentation separates them from releasing hormones, listing anamorelin, capromorelin, ibutamoren, ipamorelin, lenomorelin, macimorelin and tabimorelin as secretagogues and mimetics, and CJC-1293, CJC-1295, sermorelin and tesamorelin as releasing-hormone analogs.

What that grouping tells you: the categories are recognized well enough to be enumerated by name in a regulatory document. Recognition is not approval.

The two exceptions in that grouping: tesamorelin, a releasing-hormone analog approved for one HIV-related indication, and macimorelin, a secretagogue approved as a diagnostic agent for adult growth hormone deficiency. The remaining names on the list hold no US approval we could find.

Are any growth hormone peptides FDA approved?

More than most comparisons admit. Somatropin products are, across the indications listed above. Tesamorelin is, for excess abdominal fat in HIV lipodystrophy. Macimorelin is, as a diagnostic agent for adult growth hormone deficiency rather than as a treatment. The long-acting growth hormone analogs the Prohibited List names, lonapegsomatropin, somapacitan and somatrogon, are approved as well. What we found no US approval for is any growth hormone fragment, and any releasing-hormone analog other than tesamorelin.

What that changes downstream: where there is no approval there is no label, and where there is no label there is no route, no site list, no gauge spec and no dosing table with a regulatory reviewer behind it.

Where the approved ones do publish that detail: the somatropin and tesamorelin labels, which our injection sites page reads side by side.

How does anti-doping classify the two?

Together, and in the same class. The 2026 Prohibited List places growth hormone, its analogs and its fragments in class S2.2.3, and growth hormone releasing factors in S2.2.4, both inside the peptide hormones section that is prohibited at all times, in and out of competition. The list states that every prohibited substance in S2 is a non-Specified Substance.

The named examples: S2.2.3 lists lonapegsomatropin, somapacitan and somatrogon as analogs, and AOD-9604 and hGH 176-191 as fragments. S2.2.4 lists the releasing hormones and secretagogues above.

Why the two documents do not line up: an approval answers whether a product may be marketed for a stated use, while the Prohibited List enumerates substances by name inside effect-based classes. A compound with no approval and no label can still be listed by name in the second document.

Does the growth hormone statute cover peptides generally?

No, and the drafting is unusually tight about it. Paragraph (4) of 21 U.S.C. 333(e) defines human growth hormone for that subsection as somatrem, somatropin, or an analogue of either of them. The first two are named products. The third, "an analogue of either", is open-ended, and its reach is not settled by the text alone.

What the definition turns on: whether a compound is somatrem, somatropin, or an analogue of either. A releasing factor and a secretagogue act on the axis without being the hormone, though whether either falls inside "analogue" is exactly the open question, and we do not answer it here.

Why we stop there: how far the phrase "an analogue of either" reaches is a legal question about specific facts, and a reference page is the wrong place to answer it.

Sources

What this page is built from: seven prescribing information documents, one entry holding the three long-acting growth hormone analog labels, one federal statute, one published trial and the current Prohibited List. Every figure above traces to one of them.

Last reviewed: 27 July 2026.

1
Genotropin (somatropin) for injection, for subcutaneous use. Prescribing information, Pfizer. Sections 1, 11, and 12.3. DailyMed SPL, set id ffebf88b-d257-4542-9808-74d9b7167765.
2
Norditropin (somatropin) injection, for subcutaneous use. Prescribing information, Novo Nordisk. Sections 1, 5.1, 11, 12.2, and 12.3. DailyMed SPL, set id 1058e17c-9261-459c-a3e6-fae38d196c14.
3
Egrifta SV (tesamorelin) for injection, for subcutaneous use. Prescribing information, Theratechnologies. Sections 1, 11, 12.1, and 12.3. DailyMed SPL, set id 3d783378-b02d-4f19-99dd-0fc91a042224.
4
Mounjaro (tirzepatide) injection, for subcutaneous use. Prescribing information, Eli Lilly and Company. Section 11. DailyMed SPL, set id d2d7da5d-ad07-4228-955f-cf7e355c8cc0.
5
Ozempic (semaglutide) injection, for subcutaneous use. Prescribing information, Novo Nordisk. Section 11. DailyMed SPL, set id adec4fd2-6858-4c99-91d4-531f5f2a2d79.
6
Sandostatin (octreotide acetate) injection. Prescribing information, Novartis. Section 11. DailyMed SPL, set id 4e2c9856-1836-49f0-9472-4dbeeb408f39.
7
Macrilen (macimorelin) for oral solution. Prescribing information, Aeterna Zentaris GmbH. Sections 1 and 11. DailyMed SPL, set id aeb30f1a-4815-47ae-a2cb-b6b4e26372e1.
8
The three long-acting growth hormone analogs named in class S2.2.3, each label read for its product name, active ingredient description and Initial U.S. Approval year. Skytrofa (lonapegsomatropin-tcgd) for injection, 2021, set id 9229f871; Sogroya (somapacitan-beco) injection, 2020, set id eadd03b4; Ngenla (somatrogon-ghla) injection, 2023, set id 06dce529.
9
Falutz J, Allas S, Blot K, et al. Metabolic effects of a growth hormone-releasing factor in patients with HIV. N Engl J Med. 2007;357(23):2359-2370. doi:10.1056/NEJMoa072375. PMID 18057338.
10
Prohibited Distribution of Human Growth Hormone, 21 U.S.C. 333(e), paragraphs (1) to (4). law.cornell.edu/uscode/text/21/333.
11
World Anti-Doping Agency. World Anti-Doping Code International Standard Prohibited List 2026, in effect 1 January 2026. Classes S2.2.3 and S2.2.4. wada-ama.org/en/prohibited-list.

The disclaimer

Every page is reviewed by medical professionals before it ships, and written with longtime biohackers who were doing this before it was a trend. Reviewed still does not mean prescribed: nothing here is medical advice.

It is research, trial data, and reported use, with the numbers intact so you can check them. For decisions about your body, see a doctor who can look at your labs.