Case Study 38.2 — Five Compounds, One Phrase: "Not FDA Approved"
What this case examines: the same four words applied to five real compounds from this book, demonstrating that the phrase carries five different evidentiary meanings and that flattening them into one is the most common error in the peptide conversation.
A note before starting. This describes United States regulatory status as it stands at the time of writing, in 2026. Status differs by jurisdiction and changes. Nothing here is legal advice, and nothing here tells any reader what they may lawfully buy, import, or possess. Verify anything that matters to you against current rules in your own jurisdiction.
The exercise
Below are five compounds. Every one of them can accurately be described, in some context, as "not FDA approved." Read each entry and then ask yourself the only question that matters: what does the phrase mean here, and does it tell me anything about the molecule?
Compound 1 — BPC-157: never submitted
Status. As of this writing, no application has been submitted for approval as a drug in the United States. There is no rejection on file. There is no adverse regulatory finding on the merits of the molecule as a therapeutic. There is no file.
What produced this. Not obstruction. The chain from §38.10: no one submitted, because no one funded the trials, because there is no patentable commercial position in a short sequence published decades ago and cheap to synthesize (Chapters 32 and 36). A sponsor spending the sums a development program requires needs a route to recovering them, and this molecule does not offer one.
What it tells you about the molecule. Nothing. An empty file is exactly as consistent with an inert compound as with a useful one.
What is separately true. Chapter 17 rates the healing claims ❌, and that rating rests on the published human literature, which is essentially absent for those claims. It does not rest on the regulatory status, would not change if the regulatory status changed, and would change if an adequate randomized human trial were published. Also separately true: BPC-157 was added to the WADA Prohibited List under S0, effective from the 2022 List — prohibited because it is unapproved, with no clause anywhere about efficacy (§38.8).
Three facts, three sources, zero causation between them. That is the whole discipline.
Compound 2 — Bremelanotide, intranasal: developed, then abandoned
Status. The intranasal formulation of bremelanotide is not approved. Development was discontinued in 2008 after increases in blood pressure were observed in studies of that formulation. A subcutaneous formulation was subsequently developed and approved in the United States in 2019 for hypoactive sexual desire disorder in premenopausal women (Chapter 24).
What produced this. Evidence. Somebody ran the studies, the studies produced a finding, and the finding ended that formulation's development. This is the nearest of the five to §38.4's case (2) — and note the precision required: development was discontinued by the sponsor after negative findings, which is not identical to a formal agency rejection. The distinction matters, and a careful reader insists on it, because "the FDA rejected it" and "the company stopped" are different claims with different implications about who judged what.
What it tells you about the molecule. Something real, and something narrower than people assume. It tells you that that formulation, at those exposures had a problem. It did not tell anyone that the molecule was useless — which is why the same active compound, delivered differently, was later approved.
The lesson embedded here. Non-approval attached to a formulation is not non-approval attached to a molecule. Route, formulation, and exposure are part of what gets judged (Chapter 4).
Compound 3 — Thymosin alpha-1: approved elsewhere, not here
Status. Thymosin alpha-1 is a registered medicine in a number of jurisdictions and is not approved in the United States (Chapter 18).
What produced this. This is §38.4's case (3), and it has at least two candidate explanations that look identical from outside.
Explanation one: different agencies applied different evidence standards to the available data and reached different conclusions. Explanation two: no sponsor built and filed a United States dossier, for reasons of market size, cost, patent position, or the absence of a commercial partner.
Both are common. They are not equivalent. And the marketing that cites the foreign registrations almost never distinguishes them, because the undifferentiated version is more useful: "approved in [country]" reads as vindication, while "nobody filed here" reads as an absence.
What it tells you about the molecule. That somebody's regulator saw a dossier and said yes. That is more than an empty file. It is not a description of how large the dossier was, what standard it was judged against, or what endpoints it rested on — and, per §38.9, registration standards vary substantially between systems.
The move to make. Take the foreign approval as a pointer, then go read the assessment it points at.
Compound 4 — Growth hormone: approved, but not for this use
Status. Recombinant human growth hormone is an approved drug in the United States and elsewhere, for a defined set of indications — growth hormone deficiency, certain growth disorders, and others (Chapter 14). It is not approved for the uses that dominate its consumer marketing: anti-aging, general "optimization," body composition in healthy adults.
What produced this. Case (4). The molecule is approved; those uses are not on the label. Ordinarily this would be a straightforward off-label situation (§38.5), lawful for prescribers exercising clinical judgment even where unsupported by evidence.
The wrinkle worth knowing. Growth hormone is unusual among approved drugs in the United States in that its distribution for uses other than those authorized is specifically restricted by statute — an express exception to the general off-label picture, enacted because of exactly the marketing described above. As of this writing, that restriction exists; its precise scope and its enforcement history are matters for people qualified to read the current law, and this book does not advise on them.
What it tells you about the molecule. That the approved uses were supported well enough to be approved, and that the popular uses are a separate question with separate evidence — which Chapter 14 examines and finds much thinner than the marketing implies.
Why this entry matters most for a general reader. Case (4) is the case most often confused with case (1), in both directions. People treat off-label use of an approved drug as though it were an unapproved experimental compound, and people treat unapproved experimental compounds as though they were merely off-label. The phrase "not FDA approved" covers both, identically, which is precisely the problem.
Compound 5 — GHK-Cu in a cosmetic serum: not a drug at all
Status. A copper tripeptide sold as a cosmetic ingredient is not an unapproved drug. It is not a drug in the regulatory sense at all, and "approved" was never the applicable category (Chapter 30).
What produced this. Cosmetics sit under a different framework, one that in the United States generally does not involve premarket approval of the product. That framework comes with a hard constraint attached: what may be claimed. A product that makes a therapeutic claim — that it treats, prevents, or alters the structure or function of the body in a medical sense — risks being treated as an unapproved drug precisely because it made the claim. This is why cosmetic marketing copy has the distinctive shape it does, full of "the appearance of" and "helps support."
What it tells you about the molecule. Nothing at all about efficacy. Chapter 30's evaluation of cosmetic peptides is done entirely on the published evidence, and the regulatory category tells you only which rulebook the product is being sold under.
The trap. Saying "it's not FDA approved" about a face serum sounds like an accusation and is merely a category description — like saying a bicycle has not been certified airworthy.
The five, side by side
COMPOUND CASE WHAT THE PHRASE MEANS HERE SIGNAL ABOUT MOLECULE?
──────────────────── ───── ───────────────────────────────── ──────────────────────
BPC-157 (1) nobody filed none
bremelanotide (IN) (2)* studies were run; findings ended yes — narrow, and about
that formulation a FORMULATION
thymosin alpha-1 (3) registered elsewhere; either a ambiguous — must ask
different standard or no filing which story applies
growth hormone (4) approved drug, unapproved use none about the molecule;
the USE has its own
evidence
GHK-Cu (cosmetic) (5) not a drug at all none — wrong category
* discontinued by the sponsor after negative findings, which is adjacent to but not
identical with a formal agency rejection. The distinction is load-bearing.
Five compounds. One phrase. Five meanings, only one of which is a negative finding about a molecule — and even that one is narrower than it sounds.
"Not FDA approved" is a statement about a regulatory file, not about a molecule.
Discussion Questions
1. Rank the five compounds by how much the phrase "not FDA approved" tells you about the molecule itself, from most to least. Defend your ordering, and say explicitly where two entries are close enough that the ranking is arbitrary.
2. The bremelanotide entry insists on the distinction between "the sponsor discontinued development after negative findings" and "the agency rejected the application." Is that distinction worth the pedantry? Construct one situation in which conflating them would materially mislead someone, and one in which it would not matter.
3. For thymosin alpha-1, the two candidate explanations look identical from outside. Design a research procedure — what you would look for, and where — that would let you distinguish them for a specific compound. Then say honestly how often you think a general reader could actually complete it.
4. Growth hormone is an approved drug whose most-marketed uses are not on its label, and its distribution for unapproved uses is specifically restricted in the United States. Why might a legislature carve out an exception to the general off-label permission for one particular drug? What would have to be true about a drug for that to be a proportionate response, and what does the carve-out cost?
5. The GHK-Cu entry compares "not FDA approved" applied to a cosmetic with "not certified airworthy" applied to a bicycle. Is that comparison fair? Identify what it gets right and where it breaks down — in particular, consider a serum whose marketing implies a therapeutic effect.
6. A friend sends you a single sentence: "None of these peptides are FDA approved." Write your reply in under 150 words. It must be accurate about all five cases, must not tell your friend anything about what they may legally do, and must end by moving the conversation to evidence rather than to paperwork.