Chapter 17 — Quiz

Twenty-four questions.

Multiple choice

1. BPC-157 is: a) a 9-amino-acid peptide b) a 15-amino-acid peptide (pentadecapeptide) c) a 30-amino-acid peptide d) a small protein of 51 residues

2. The sequence GEPPPGKPADDAGLV contains four prolines including a run of three. The structural consequence is that: a) the molecule forms an unusually stable alpha helix b) the molecule cannot form a normal alpha helix through that region and is rigid there c) the molecule forms a beta sheet d) the molecule folds into a disulfide-stabilized loop

3. BPC-157 has never been assigned a generic drug name. This is: a) strong evidence that the molecule is pharmacologically inert b) strong evidence about regulatory history and no evidence about pharmacology c) evidence that the compound is unsafe d) a naming oversight with no informational content

4. As of this chapter's writing, the number of completed, peer-reviewed, randomized controlled human trials of BPC-157 in the published literature, for all indications combined, is: a) zero b) one c) three to five d) more than ten

5. A receptor for BPC-157 has: a) been identified and structurally characterized b) been identified but not yet crystallized c) not been definitively established; proposed mechanisms are inferred from downstream observations d) been ruled out entirely

6. Roughly what proportion of compounds that enter human clinical trials never reach approval? a) one in ten b) three in ten c) five in ten d) nine in ten

7. Chapter 5's least-discussed reason animal results fail to transfer is: a) different biology b) different dose c) different endpoint d) different publication pressure

8. Preclinical animal research is largely unregistered. The consequence for interpreting the published literature is that: a) the studies are lower quality b) the published record is a filtered sample from a population of unknown size c) peer review is weaker d) the results cannot be replicated

9. A surgically transected rat Achilles tendon differs from human chronic mid-portion Achilles tendinopathy in that the rodent injury is: a) chronic, partial, and degenerative b) acute, complete, and with a known time zero c) identical but smaller d) inflammatory in the same way but slower

10. The term "tendinopathy" replaced "tendinitis" in the clinical literature primarily because: a) it is easier to pronounce b) chronic tendon disorders often show degenerative change and relatively little classic inflammation c) insurers required it d) the older term implied surgery

11. Of the five barriers facing a swallowed peptide, a stability argument based on protease resistance addresses: a) all five b) barriers 1–3 (acid/pepsin, pancreatic proteases, brush-border peptidases) c) barrier 4 (crossing the epithelium) d) barrier 5 (hepatic first pass)

12. Stability and bioavailability are: a) synonyms b) different claims, and a molecule can be entirely stable with zero bioavailability c) different claims, but stability always implies some bioavailability d) both measured by the same assay

13. A rodent study showing that an orally administered peptide protects gastric mucosa is compatible with: a) high systemic bioavailability only b) the compound acting locally in the gut with zero systemic absorption c) proof of delivery to distant tissue d) proof that the compound crosses the epithelium

14. "No reported harm" from gray-market use of BPC-157 is close to uninformative because: a) users are dishonest b) there is no systematic collection, no reporting pathway, and no known denominator c) the effects are always delayed d) reports are legally suppressed

15. On the question of whether BPC-157 causes or accelerates cancer in humans, the accurate statement is: a) it has been shown not to b) it has been shown to c) there is no evidence either way because the studies that would look have not been done d) animal studies settle the question

16. In the rating system, ❌ means: a) the molecule does not work b) the molecule is dangerous c) the confident version of the claim is not supported by human evidence d) the compound is fraudulent

17. A registration on a clinical trials registry establishes that: a) a trial was completed b) results exist c) someone filed a plan to run a study d) the compound is approved

18. In §17.11's proposed trial, all participants in both arms would receive a standardized progressive loading program. The reason is that: a) it is ethically required b) the real-world question is whether the compound adds anything to what already works c) it reduces cost d) it improves blinding

19. In that trial, the required magnitude of the primary result is: a) any statistically significant difference b) a difference exceeding the instrument's minimal clinically important difference, with the trial powered for it c) a doubling of the score d) any improvement on imaging

20. An adequately powered, well-conducted null result in that trial would move the rating to: a) ⚠️ b) ✅ c) a different and more informative ❌ d) 🔬

True or false

21. A thousand rat studies and one rat study make the same claim about humans. (True / False)

22. Because no pharmaceutical company can patent BPC-157, the absence of human trials should be treated as evidence in the compound's favor. (True / False)

23. The identity, purity, potency, sterility, and endotoxin risks of gray-market material are independent of whether the molecule itself has any biological activity. (True / False)

24. A conference abstract reporting a positive human result would be sufficient to move the rating from ❌ to ⚠️. (True / False)

Answer key **1. b)** Fifteen amino acids — a pentadecapeptide, GEPPPGKPADDAGLV, about 1,419 Da. (§17.2) **2. b)** Proline's side chain bonds back to the backbone nitrogen, removing that stretch from the hydrogen-bonding pattern an alpha helix requires. Rigid, not helical. (§17.2, Ch 1 §1.2) **3. b)** This is the distinction the chapter insists on preserving exactly. A naming authority assigns a stem name during serious clinical development; the absence of one is a fact about regulatory history. It is not a laboratory finding and says nothing about activity. Read in the wrong direction it is a non sequitur. (§17.2, Ch 1 §1.8) **4. a)** Zero, for all indications combined. There is also no published Phase I safety study. (§17.6) — and the correct response to this answer is to go check it yourself, since the claim is date-stamped and falsifiable. **5. c)** Proposed mechanisms involve nitric-oxide-related pathways, growth-factor and angiogenic signaling, and others, all inferred from downstream observations in animal models. This is why the dossier's Field 3 entry should read "not established." (§17.2) **6. d)** Roughly nine in ten — and that describes compounds that had already cleared preclinical work and attracted funding. Attrition from "promising animal result" is steeper still. (§17.1) **7. d)** Different publication pressure. It is least discussed because it is invisible: it concerns the studies you never see. (§17.5, Ch 5 §5.3) **8. b)** There is no registry of preclinical experiments, no obligation to publish null results, and little incentive to. So consistency in the published record is exactly what a filter would produce, and the published record cannot distinguish a robust effect from a small one plus selective publication. (§17.5) **9. b)** Acute, complete, clean, surgically produced, with a known time zero, in a healthy young animal under controlled activity. The human problem is chronic, partial, degenerative, developed over months or years, in a person who keeps using the limb. (§17.7) **10. b)** The change of name reflected a change in understanding of the pathology: degenerative change, disorganized collagen, altered matrix, and often abnormal neovascularization, with relatively little classic inflammation. (§17.7) **11. b)** Protease resistance addresses degradation — barriers 1 through 3. Barrier 4 is permeability, an entirely different physical property, and barrier 5 is hepatic first pass. (§17.8, Ch 4) **12. b)** Stability asks whether the molecule remains intact; bioavailability asks what fraction reaches systemic circulation unchanged. An indestructible molecule that cannot cross an epithelium has zero bioavailability. Conflating the two is the load-bearing error in oral peptide marketing. (§17.8) **13. b)** The most parsimonious reading of a local gut effect is that the compound acted where it was sitting. Systemic absorption, survival of first-pass metabolism, distribution, and arrival at a distant hypovascular tissue in meaningful concentration are four additional claims, none of which follows. (§17.8) **14. b)** "No reported harm" is a statement about a reporting system. For an unapproved compound purchased outside any regulated supply chain, there is no systematic collection, no pharmacovigilance pathway that fits, strong disincentives to disclosure, and no denominator. Compare an approved drug, where "no signal across two million patient-years" is genuinely informative. (§17.9) **15. c)** Both fabrications should be rejected: the person claiming it is carcinogenic and the person claiming the question is closed. It is a live unknown, and it is the kind of question a trial is designed to address. (§17.9) **16. c)** ❌ describes the state of the evidence, not the state of the molecule. Several ❌ compounds in this book may be ⚠️ or ✅ in a decade; some will be shown not to work. The rating does not tell you which. (§17.10, Ch 5) **17. c)** A plan. Registered, run, completed, results-posted, and peer-reviewed publication are five distinct achievements, and only the last settles anything. Check the status field and look for a results tab. (§17.6) **18. b)** A trial against nothing answers a question nobody is asking. The real question is incremental benefit over the best-supported existing treatment, which for chronic Achilles tendinopathy is a structured progressive loading program. (§17.11) **19. b)** A statistically significant difference smaller than the MCID is a real finding about biology and not a reason for anyone to do anything. The trial must be powered for the clinically meaningful difference, with the calculation published in the pre-registration. (§17.11) **20. c)** "Tested and did not work" is a different and far more informative ❌ than "untested." Note that the rating symbol does not change while the epistemic situation changes enormously — which is a limitation of any four-tier system, and a reason the one-sentence reason line is not optional. (§17.11) **21. True.** Studies on the animal rung accumulate confidence *within* that rung. They do not promote a claim to the rung above by accumulation. This is why regulators require human trials from compounds with immaculate preclinical packages. (§17.5) **22. False.** The premise is largely correct — the absence of trials here really is closer to a funding artifact than a scientific verdict — and the conclusion does not follow. If unfunded status upgraded a rating, every unfunded compound would be upgraded, including the great majority that do not work. It is a reason to want the trial run, not a reason to act as though it had been. (§17.10, §17.11) **23. True.** They would apply equally to a vial of sterile saline mislabeled as a peptide. This is why "peptides break down into amino acids, so they're safe" misses the point: the documented harm in this market has come overwhelmingly from what else was in the vial. (§17.9, Ch 6, Ch 19) **24. False.** Abstracts are short, lightly reviewed if at all, frequently never followed by a full publication, and often differ from the eventual paper. An abstract is a promissory note. The rating moves on a completed, adequately powered, pre-registered, peer-reviewed randomized trial with a pre-specified functional endpoint — and a poor-quality human trial moves nothing in either direction. (§17.6, §17.11)