# Unstudied peptides carry sterility and biological risks

Markdown copy of https://realalpha.app/s/unstudied-peptides-carry-sterility-and-biological-risks/ on Real Alpha, the best minutes from long interviews with the people building AI. Cite and link the page, not this copy.

- Speaker: [Morgan McSweeney](https://realalpha.app/people/morgan-mcsweeney/) · Morgan McSweeney is a pharmaceutical scientist and medfluencer. · Translates medical evidence for the public and advises organizations, including the WHO and White House science office.
- Host: [Neil deGrasse Tyson](https://realalpha.app/people/neil-degrasse-tyson/)
- Host: [Chuck Nice](https://realalpha.app/people/chuck-nice/) · Comic
- Host: Gary O'Reilly · Comic
- Show: StarTalk
- Episode: [The Science of Looksmaxxing, with Doc Noc](https://realalpha.app/v/ESvls8ZUg58/), Oct 24, 2026
- Moment: 27:42 to 30:53 of the episode (3 min), playing on https://realalpha.app/s/unstudied-peptides-carry-sterility-and-biological-risks/; the episode from there: https://realalpha.app/v/ESvls8ZUg58/?t=1662

## Quote

> “Not to say that it causes cancer or that it exacerbates cancer among people who have cancer who take it, but **I wouldn't rule that out**.”
> — [Morgan McSweeney](https://realalpha.app/people/morgan-mcsweeney/) at [29:38](https://realalpha.app/v/ESvls8ZUg58/?t=1778) · StarTalk

## Takeaways

1. Research-grade vials may be nonsterile or contain bacterial endotoxin.
2. BPC-157 is promoted for tissue repair; its possible angiogenesis raises a theoretical concern.
3. He says cancer effects are unproven and need formal clinical studies.

## About this segment

Morgan McSweeney describes contamination risks in research-grade vials and a theoretical concern that BPC-157's possible effect on blood-vessel growth could support tumors. He says cancer effects are unproven.

From “The Science of Looksmaxxing, with Doc Noc”, Oct 24, 2026. [Watch the full episode](https://realalpha.app/v/ESvls8ZUg58/)

## Transcript

Transcribed by machine (Whisper) from the episode’s audio, so a word may be off here and there.

[27:54](https://realalpha.app/v/ESvls8ZUg58/?t=1674) Are peptides that people are using for their body composition naturally occurring in our bodies? Are they being pharmaceutically developed and then introduced? Most of them are modified based on naturally occurring molecules, is my understanding. So they're changing the signaling. And so if I want to reduce fat, you make the signal of reducing the fat and triggering the chemicals in the body. To make it more powerful, to make it last longer.

[28:23](https://realalpha.app/v/ESvls8ZUg58/?t=1703) Now, for these, what could be compounded peptides, and I think these very differently from the type of peptides like GLP-1s, the ones we're talking about that have minimal human data, that have animal data, that people are self-dosing with kind of through the gray market, I'm very concerned about that. There's two big types of risks. The first one, which is the one that people talk about the most, is the less concerning risk.

[28:43](https://realalpha.app/v/ESvls8ZUg58/?t=1723) That's where, you know, it's being made in these for research use only applications, but they're actually marketing it to people for personal research. The risk is, well, maybe they didn't do a good job of being sterile in their preparations. Maybe there's some inflammatory endotoxin from the bacteria they use to produce the peptides. Maybe what's in the vial isn't safe to inject. That type of risk you can mitigate by bringing it domestically in regulated pharmacies, compounding it here.

[29:08](https://realalpha.app/v/ESvls8ZUg58/?t=1748) The second type of risk is much more concerning to me, which is that some of these peptides, they're touted for things like tissue repair, Like BPC-157, it gets pitched as, oh, it's going to help you recover from your tendon injury or your muscle injury. Athletes would be very interested in that. Right. Which, you know, on the benefit side, that could be great. One of the things is, you know, they say it may promote angiogenesis, the growth of new blood vessels, which is good in the context of tissue repair where you need to get nutrients in an immune cell to help.

[29:36](https://realalpha.app/v/ESvls8ZUg58/?t=1776) Yeah, I can see that, yeah. On the flip side, cancer biologists think of angiogenesis in a very different light. Absolutely. And so if you have a particularly well-vascularized tumor, that can lead to runaway tumor growth in a way that wouldn't happen. Because you're feeding the tumor. Not to say that it causes cancer or that it exacerbates cancer among people who have cancer who take it, but I wouldn't rule that out.

[29:58](https://realalpha.app/v/ESvls8ZUg58/?t=1798) Yeah, that risk is definitely there. For sure. So, I mean, clearly they have biological activity, but having biological activity is not a compliment when it's coming from a biologist. It could have benefits. It could have risks. I would want to see a very carefully studied and objectively studied weighing of those benefits and risks in formal clinical studies before I would take any of these types of...

[30:20](https://realalpha.app/v/ESvls8ZUg58/?t=1820) Is there a list of the good guys and the bad guys when it comes to peptides? Yeah, so all of the ones that you're going to be buying from these gray market, research-grade sources, I wouldn't touch them for the reason of both of those risks. Because some of them, you can even buy like redditrutide or trisepatide or semaglutide, the ones that are the real GLP-1 drugs. And it may be cheaper to get it through these unofficial sources,