Peptides are not steroids. They are made of amino acids, while steroids are derived from cholesterol. This guide compares the two, and explains how growth hormone and its releasing peptides fit in.
Written by the Peptide Labs Research Team
No. Peptides and steroids are chemically unrelated classes of molecule. The confusion comes from their appearing together in the same corners of sport, supplement and regulatory discussion, and from the fact that both include hormones. They differ in what they are made of, how they are made in the body, and how they signal.
| Peptides | Steroids | |
|---|---|---|
| Built from | Amino acids | A four-ring carbon structure derived from cholesterol |
| Chemical class | Protein-like chains | Lipids |
| Typical receptor location | Cell surface | Inside the cell (cytoplasm or nucleus) |
| Typical speed of onset in signalling | Often fast, via second messengers | Often slower, via gene transcription |
| Examples | Insulin, oxytocin, GLP-1, growth hormone-releasing hormone | Testosterone, oestradiol, cortisol |
Peptide hormones are water-soluble and generally cannot cross the cell membrane, so they bind receptors on the cell surface and trigger signalling inside. Steroid hormones are lipid-soluble, cross the membrane, and bind receptors inside the cell that then act on gene expression.
Human growth hormone (somatropin) is a 191-amino-acid protein hormone made by the pituitary. It is not a steroid. It is also not one of the short research peptides, but it sits upstream of several of them in the growth hormone axis:
So "HGH peptides" in search terms generally refers to GHRH analogues and ghrelin mimetics studied for their effect on endogenous growth hormone secretion, not to growth hormone itself. See Ipamorelin vs CJC-1295 vs Sermorelin and growth hormone axis research.
Sporting bodies group both families together because both can appear on prohibited lists. The World Anti-Doping Agency lists growth hormone, its releasing factors and a number of unapproved peptides in its prohibited substances categories, alongside anabolic agents. Being on the same list does not make them the same kind of molecule, and the lists change annually, so athletes should check the current version.
Regulation attaches to the substance, not the category label. Anabolic steroids are listed in the Poisons Standard, and several peptides and peptide hormones are also scheduled, including some that have been added in recent years. "Sold for research" is not an exemption. See are research peptides legal in Australia and check the current Poisons Standard.
Are peptide hormones the same as steroid hormones?
No. Peptide hormones are amino acid chains acting at surface receptors. Steroid hormones are cholesterol-derived lipids acting at intracellular receptors.
Is HGH a steroid?
No. It is a 191-amino-acid protein hormone.
Are peptides or HGH more heavily regulated?
Both are subject to scheduling and prohibited-list rules that depend on the specific substance. There is no blanket answer for the whole class.
For a broader introduction, see what are peptides.
Disclaimer: All compounds referenced are supplied for in-vitro laboratory research only and are not for human or veterinary use. This article is educational and is not medical or legal advice.
Peptides are short chains of amino acids. This guide covers what they are, how they differ from proteins, the main classes studied in research, and how quality is verified.
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